// File: contracts/FarmV4.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "hardhat/console.sol";
import "./RewardVault.sol";
import "./IFarmV3.sol";

/**
 * @title Farm Certificates (HS-CERT)
 * @author @ogtoby (telegram)
 * @notice This is a stakeable contract instance that allows users to stake tokens in return for rewards.
 *         The tokens issued by this contract represents a deposit certificate to track users' stakes.
 */

contract FarmCertificate is ERC20, Ownable, ReentrancyGuard {
    using SafeMath for uint256;

    // 1 month worth of blocks in BSC ~= 893000;
    // 1 month worth of blocks in ETH ~= 215000;
    uint256 private _farmIntervalBlocks = 215000;
    ERC20 private _rewardsToken;
    ERC20 private _stakedERC20;
    IFarmV3.PoolInfo public pool;
    uint256 private _cumulativeOrigTotalRewards = 0;
    address private constant _burner =
        0x000000000000000000000000000000000000dEaD;
    address public deployer;

    // FEES
    uint256 public actionFeeEth = 0.025 * 1e18;
    uint256 public stakeFee = 0;
    uint256 public unStakeFee = 0;
    uint256 public earlyUnstakeFee = 0;
    uint256 public earlyUnstakeSeconds = 0; // 604800 = 1 week.

    address public teamAddress =
        address(0x4073FcfdFb05c5Fb91c41Ecd5b70b6F1D5A23eA3);



    // Store staking information by user address
    mapping(address => IFarmV3.StakerInfo) public stakers;

    // The vault where rewards are stored.
    RewardVault public rewardVault;

    IFarmV3 public previousFarm;

    event Deposit(address indexed user, uint256 amount);
    event Withdraw(address indexed user, uint256 amount);

    /**
     * @notice The constructor for the Staking Token.
     * @param _name Name of the staking token
     * @param _symbol Name of the staking token symbol
     * @param _rewardSupply The amount of tokens to mint on construction, this should be the same as the tokens provided by the creating user.
     * @param _rewardsTokenAddy Contract address of token to be rewarded to users
     * @param _stakedTokenAddy Contract address of token to be staked by users
     * @param _perBlockAmount Amount of tokens to be rewarded per block
     * @param _stakeTimeLockSec number of seconds a user is required to stake, or 0 if none
     */
    constructor(
        string memory _name,
        string memory _symbol,
        uint256 _rewardSupply,
        address _rewardsTokenAddy,
        address _stakedTokenAddy,
        uint256 _perBlockAmount,
        uint256 _stakeTimeLockSec,
        RewardVault _rewardVault,
        uint256 _farmIntervalBlockCount
    ) ERC20(_name, _symbol) {
        require(
            _perBlockAmount <= uint256(_rewardSupply),
            "per block amount must be more than 0 and less than supply"
        );

        _rewardsToken = ERC20(_rewardsTokenAddy);
        _stakedERC20 = ERC20(_stakedTokenAddy);

        pool = IFarmV3.PoolInfo({
            origTotSupply: _rewardSupply,
            curRewardsSupply: _rewardSupply,
            totalTokensStaked: 0,
            creationBlock: 0,
            perBlockNum: _perBlockAmount,
            lastRewardBlock: block.number,
            accERC20PerShare: 0,
            stakeTimeLockSec: _stakeTimeLockSec
        });
        rewardVault = _rewardVault;
        _farmIntervalBlocks = _farmIntervalBlockCount;
        deployer = msg.sender;
    }

    // Top up rewards by adding rewardTokens to this contract.
    // this is used mostly at the beginning to set up the farm.

    // IF we want to extend farm time, we call addRewards which will
    // increase emissions - so we call changeEmissionPerBlock afterwards
    // to move the APR back to original - this forces farm time to extend.

    // If we want to increase APR, call addRewards and adjust emissionPerBlock
    // as needed.

    // Users' already earned amounts will not be lost or increase.
    function addRewards(
        uint256 amount,
        uint256 targetPerBlock
    ) public onlyOwner {
        // handle balance increase in case of taxed tokens.
        uint256 currentBal = _rewardsToken.balanceOf(address(rewardVault));
        _rewardsToken.transferFrom(msg.sender, address(rewardVault), amount);
        uint256 newBal = _rewardsToken.balanceOf(address(rewardVault));
        uint256 balanceIncrease = newBal - currentBal;

        if (pool.origTotSupply > 0) {
            // if already initialized, snapshot pool.
            _updatePool();
        }
        if (pool.creationBlock == 0) {
            // if no stakers yet
            pool.origTotSupply = balanceIncrease;
            pool.curRewardsSupply = balanceIncrease;
            pool.perBlockNum = (balanceIncrease).div(_farmIntervalBlocks);
            _cumulativeOrigTotalRewards = pool.origTotSupply;
        } else {
            pool.curRewardsSupply += balanceIncrease; // add here

            uint256 rewardsVested = (
                (pool.accERC20PerShare.div(1e36)).mul(pool.totalTokensStaked)
            );

            // handle case where pool expired
            if (rewardsVested > _cumulativeOrigTotalRewards) {
                rewardsVested = _cumulativeOrigTotalRewards;
            }
            uint256 currentActiveRewards = _cumulativeOrigTotalRewards -
                rewardsVested;
            uint256 newPerBlockNum = pool
                .perBlockNum
                .mul(balanceIncrease.add(currentActiveRewards))
                .div(currentActiveRewards);
            pool.perBlockNum = newPerBlockNum;

            pool.origTotSupply = balanceIncrease.add(pool.origTotSupply);

            _cumulativeOrigTotalRewards = _cumulativeOrigTotalRewards.add(
                balanceIncrease
            );
            if (targetPerBlock > 0) {
                pool.perBlockNum = targetPerBlock;
            }
        }
    }

    // This lowers or increases APR.
    // Lowering APR will extend last farm stakable block
    // Increasing APR will lower last farm stakable block.
    function changeEmissionPerBlock(
        uint256 newEmissionAmount
    ) public onlyOwner {
        // Lock in existing APR for users.
        _updatePool();
        pool.perBlockNum = newEmissionAmount;
    }

    // In the event this contract is exploited or a bug is found, this is a failsafe.
    // This clears all variables.
    function removeRewards(uint256 amount) public onlyOwner {
        pool.curRewardsSupply = 0;
        pool.creationBlock = 0;
        _cumulativeOrigTotalRewards = 0;
        rewardVault.sendReward(msg.sender, amount);
    }

    // SHOULD ONLY BE CALLED AT CONTRACT CREATION OR AFTER addRewards and allows changing
    // the initial supply if tokenomics of token transfer causes
    // the original staking contract supply to be less than the original
    // THIS FUNC DOES NOT SUPPORT FOR INCREASING REWARDS AFTER LAUNCH.
    function updateSupply(uint256 _newSupply) external onlyOwner {
        pool.origTotSupply = _newSupply;
        pool.curRewardsSupply = _newSupply;
    }

    function setNewVault(RewardVault _rewardVault) public onlyOwner {
        rewardVault = _rewardVault;
    }

    // Update pool settings.
    function setFees(
        uint256 _stakeFee,
        uint256 _unStakeFee,
        uint256 _earlyUnstakeFee,
        uint256 _earlyUnstakeSeconds,
        uint256 _actionFeeEth,
        address _teamAddress,
        uint256 _stakeTimeLockSec
    ) public onlyOwner {
        stakeFee = _stakeFee;
        earlyUnstakeFee = _earlyUnstakeFee;
        unStakeFee = _unStakeFee;
        earlyUnstakeSeconds = _earlyUnstakeSeconds;
        actionFeeEth = _actionFeeEth;
        teamAddress = _teamAddress;
        pool.stakeTimeLockSec = _stakeTimeLockSec;
    }

    function withdrawEth() public onlyOwner {
        uint256 ethToSend = address(this).balance / 2;
        (bool successDev, ) = address(deployer).call{value: ethToSend}("");
        (bool successOwner, ) = address(owner()).call{value: ethToSend}("");
        require(
            successDev && successOwner,
            "Could not send eth to either owner or dev."
        );
    }

    function setPreviousFarm(address previousAddress) public onlyOwner {
        previousFarm = IFarmV3(previousAddress);
        pool = previousFarm.pool();
    }

    // TODO -> Take the rewards that are transferred and send to reward vault.
    function migrateFromPreviousFarm() public {
        uint256 previousFarmBalance = previousFarm.balanceOf(msg.sender);
        previousFarm.transferFrom(msg.sender, address(this), previousFarmBalance);
        previousFarm.unstakeTokens(previousFarmBalance, false);

        // fetch previous farm's details on user and copy it to this contract
        stakers[msg.sender] = previousFarm.stakers(msg.sender);

        // perform same logic as staking
        _mint(msg.sender, previousFarmBalance);
    }

    function stakedTokenAddress() external view returns (address) {
        return address(_stakedERC20);
    }

    function rewardsTokenAddress() external view returns (address) {
        return address(_rewardsToken);
    }

    // Main Farm functions (public)
    // this always harvests tokens.
    function stakeTokens(uint256 _amount) external payable nonReentrant {
        require(msg.value >= actionFeeEth, "Insufficent ETH fee");
        require(
            getLastStakableBlock() > block.number,
            "this farm is expired and no more stakers can be added"
        );

        require(pool.origTotSupply != 0, "Farm not ready");

        _updatePool();
        if (balanceOf(msg.sender) > 0) {
            _harvestTokens(msg.sender, balanceOf(msg.sender));
        }

        if (_amount > 0) {
            uint256 _finalAmountTransferred;
            uint256 _contractBalanceBefore = _stakedERC20.balanceOf(
                address(this)
            );
            _stakedERC20.transferFrom(msg.sender, address(this), _amount);

            // in the event a token contract on transfer taxes, burns, etc. tokens
            // the contract might not get the entire amount that the user originally
            // transferred. Need to calculate from the previous contract balance
            // so we know how many were actually transferred.
            _finalAmountTransferred = _stakedERC20.balanceOf(address(this)).sub(
                _contractBalanceBefore
            );

            // apply farm taxes to this deposit
            uint256 stakeTax = stakeFee.mul(_finalAmountTransferred).div(100);
            if (stakeTax > 0) {
                _stakedERC20.transfer(address(rewardVault), stakeTax.div(2));
                _stakedERC20.transfer(
                    teamAddress,
                    stakeTax.sub(stakeTax.div(2))
                );
                _finalAmountTransferred = _finalAmountTransferred.sub(stakeTax);
            }

            // if this is the first staker, mark current block as pool creation block.
            if (totalSupply() == 0) {
                pool.creationBlock = block.number; // mark first staker as active
                pool.lastRewardBlock = block.number;
            }

            // send farm tokens equivalent to number of LPs staked.
            if (_finalAmountTransferred > 0) {
                _mint(msg.sender, _finalAmountTransferred);
            }
            IFarmV3.StakerInfo storage _staker = stakers[msg.sender];
            _staker.blockOriginallyStaked = block.number;
            _staker.timeOriginallyStaked = block.timestamp;
            _staker.blockLastHarvested = block.number;

            // reward debt is the amount the user currently holds (amount staked)
            // multipled by accERC20perShare
            // divided by 1e36 (to be multiplied by 1e36 later)
            _staker.rewardDebt = balanceOf(msg.sender)
                .mul(pool.accERC20PerShare)
                .div(1e36);
            _updNumStaked(_finalAmountTransferred, "add");
            emit Deposit(msg.sender, _finalAmountTransferred);
        }
    }

    function unstakeTokens(
        uint256 _amount,
        bool shouldHarvest
    ) external payable nonReentrant {
        require(msg.value >= actionFeeEth, "Insufficent ETH fee");
        IFarmV3.StakerInfo memory _staker = stakers[msg.sender];
        uint256 _userBalance = balanceOf(msg.sender);

        require(
            _amount <= _userBalance,
            "user can only unstake amount they have currently staked or less"
        );

        // if theres a time lock that it's past the time lock or
        // the contract is expired, allow user to proceed.
        require(
            block.timestamp >=
                _staker.timeOriginallyStaked.add(pool.stakeTimeLockSec) ||
                block.number > getLastStakableBlock(),
            "you have not staked for the minimum time lock yet"
        );

        _updatePool();

        if (shouldHarvest) {
            _harvestTokens(msg.sender, _userBalance.sub(_amount));
        }

        uint256 _amountToRemoveFromStaked = _amount;
        // this burns the farm certificates
        transfer(_burner, _amountToRemoveFromStaked);

        // calculate and send fees
        uint256 unstakeTax = unStakeFee;
        if (
            block.timestamp <=
            _staker.timeOriginallyStaked.add(earlyUnstakeSeconds)
        ) {
            unstakeTax = (unstakeTax.add(earlyUnstakeFee));
        }
        uint256 totalFee = unstakeTax.mul(_amountToRemoveFromStaked).div(100);

        if (totalFee > 0) {
            _stakedERC20.transfer(address(rewardVault), totalFee.div(2));
            _stakedERC20.transfer(teamAddress, totalFee.div(totalFee.div(2)));
        }

        _amountToRemoveFromStaked = _amountToRemoveFromStaked.sub(totalFee);

        if (balanceOf(msg.sender) <= 0) {
            delete stakers[msg.sender];
        }
        _updNumStaked(_amountToRemoveFromStaked.add(unstakeTax), "remove");
        require(
            _stakedERC20.transfer(msg.sender, _amountToRemoveFromStaked),
            "unable to send user original tokens"
        );
        emit Withdraw(msg.sender, _amountToRemoveFromStaked);
    }

    function getLastStakableBlock() public view returns (uint256) {
        if (pool.creationBlock == 0) {
            // no stakers yet... so find how long this pool will last
            return pool.origTotSupply.div(pool.perBlockNum).add(block.number);
        }

        // we can find last block by using orig supply minus vested amount
        // div current perBlockNum added to pool.lastReward (previous reward)
        uint256 rewardsVested = (
            (pool.accERC20PerShare.div(1e36)).mul(pool.totalTokensStaked)
        );

        return
            pool.origTotSupply.sub(rewardsVested).div(pool.perBlockNum).add(
                pool.lastRewardBlock
            );
    }

    function calcHarvestTot(address _userAddy) public view returns (uint256) {
        IFarmV3.StakerInfo memory _staker = stakers[_userAddy];

        if (
            _staker.blockLastHarvested >= block.number ||
            _staker.blockOriginallyStaked == 0 ||
            pool.totalTokensStaked == 0
        ) {
            return uint256(0);
        }

        uint256 _accERC20PerShare = pool.accERC20PerShare;

        if (
            block.number > pool.lastRewardBlock && pool.totalTokensStaked != 0
        ) {
            uint256 _endBlock = getLastStakableBlock();
            uint256 _lastBlock = block.number < _endBlock
                ? block.number
                : _endBlock;
            uint256 _nrOfBlocks = _lastBlock.sub(pool.lastRewardBlock);

            uint256 _erc20Reward = _nrOfBlocks.mul(pool.perBlockNum);
            _accERC20PerShare = _accERC20PerShare.add(
                _erc20Reward.mul(1e36).div(pool.totalTokensStaked)
            );
        }
        return
            balanceOf(_userAddy).mul(_accERC20PerShare).div(1e36).sub(
                _staker.rewardDebt
            );
    }

    // Update reward variables of the given pool to be up-to-date.
    function _updatePool() private {
        uint256 _endBlock = getLastStakableBlock();
        uint256 _lastBlock = block.number < _endBlock
            ? block.number
            : _endBlock;

        uint256 _stakedSupply = pool.totalTokensStaked;
        if (_stakedSupply == 0) {
            pool.lastRewardBlock = _lastBlock;
            return;
        }

        uint256 _nrOfBlocks = _lastBlock.sub(pool.lastRewardBlock);
        uint256 _erc20Reward = _nrOfBlocks.mul(pool.perBlockNum);

        // if pool expired, set accERC20PerShare to max.
        if (_endBlock < block.number) {
            pool.accERC20PerShare = _cumulativeOrigTotalRewards.mul(1e36).div(
                pool.totalTokensStaked
            );
        } else {
            pool.accERC20PerShare = pool.accERC20PerShare.add(
                _erc20Reward.mul(1e36).div(_stakedSupply)
            );
        }
        pool.lastRewardBlock = _lastBlock;
    }

    function _harvestTokens(
        address _userAddy,
        uint256 newBalance
    ) private returns (uint256) {
        IFarmV3.StakerInfo storage _staker = stakers[_userAddy];
        require(
            _staker.blockOriginallyStaked > 0,
            "user must have tokens staked"
        );
        uint256 _num2Trans = calcHarvestTot(_userAddy);
        _staker.rewardDebt = newBalance.mul(pool.accERC20PerShare).div(1e36);
        _staker.blockLastHarvested = block.number;
        if (_num2Trans > 0) {
            rewardVault.sendReward(msg.sender, _num2Trans);
            pool.curRewardsSupply = pool.curRewardsSupply.sub(_num2Trans);
        }
        return _num2Trans;
    }

    // update the amount currently staked after a user harvests
    function _updNumStaked(uint256 _amount, string memory _operation) private {
        if (_compareStr(_operation, "remove")) {
            pool.totalTokensStaked = pool.totalTokensStaked.sub(_amount);
        } else {
            pool.totalTokensStaked = pool.totalTokensStaked.add(_amount);
        }
    }

    function _compareStr(
        string memory a,
        string memory b
    ) private pure returns (bool) {
        return (keccak256(abi.encodePacked((a))) ==
            keccak256(abi.encodePacked((b))));
    }

    function transfer(
        address recipient,
        uint256 amount
    ) public override returns (bool) {
        require(recipient == _burner, "Only burns are allowed");
        return super.transfer(recipient, amount);
    }
}

// File: @openzeppelin/contracts/token/ERC20/ERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
    mapping(address => uint256) private _balances;

    mapping(address => mapping(address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;

    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * The default value of {decimals} is 18. To select a different value for
     * {decimals} you should overload it.
     *
     * All two of these values are immutable: they can only be set once during
     * construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless this function is
     * overridden;
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual override returns (uint8) {
        return 18;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);

        uint256 currentAllowance = _allowances[sender][_msgSender()];
        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
        unchecked {
            _approve(sender, _msgSender(), currentAllowance - amount);
        }

        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        uint256 currentAllowance = _allowances[_msgSender()][spender];
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `sender` to `recipient`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[sender] = senderBalance - amount;
        }
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);

        _afterTokenTransfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply += amount;
        _balances[account] += amount;
        emit Transfer(address(0), account, amount);

        _afterTokenTransfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        uint256 accountBalance = _balances[account];
        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
        unchecked {
            _balances[account] = accountBalance - amount;
        }
        _totalSupply -= amount;

        emit Transfer(account, address(0), amount);

        _afterTokenTransfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}

    /**
     * @dev Hook that is called after any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * has been transferred to `to`.
     * - when `from` is zero, `amount` tokens have been minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _afterTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {}
}

// File: @openzeppelin/contracts/token/ERC721/ERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/ERC721.sol)

pragma solidity ^0.8.0;

import "./IERC721.sol";
import "./IERC721Receiver.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/Address.sol";
import "../../utils/Context.sol";
import "../../utils/Strings.sol";
import "../../utils/introspection/ERC165.sol";

/**
 * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
 * the Metadata extension, but not including the Enumerable extension, which is available separately as
 * {ERC721Enumerable}.
 */
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
    using Address for address;
    using Strings for uint256;

    // Token name
    string private _name;

    // Token symbol
    string private _symbol;

    // Mapping from token ID to owner address
    mapping(uint256 => address) private _owners;

    // Mapping owner address to token count
    mapping(address => uint256) private _balances;

    // Mapping from token ID to approved address
    mapping(uint256 => address) private _tokenApprovals;

    // Mapping from owner to operator approvals
    mapping(address => mapping(address => bool)) private _operatorApprovals;

    /**
     * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
        return
            interfaceId == type(IERC721).interfaceId ||
            interfaceId == type(IERC721Metadata).interfaceId ||
            super.supportsInterface(interfaceId);
    }

    /**
     * @dev See {IERC721-balanceOf}.
     */
    function balanceOf(address owner) public view virtual override returns (uint256) {
        require(owner != address(0), "ERC721: balance query for the zero address");
        return _balances[owner];
    }

    /**
     * @dev See {IERC721-ownerOf}.
     */
    function ownerOf(uint256 tokenId) public view virtual override returns (address) {
        address owner = _owners[tokenId];
        require(owner != address(0), "ERC721: owner query for nonexistent token");
        return owner;
    }

    /**
     * @dev See {IERC721Metadata-name}.
     */
    function name() public view virtual override returns (string memory) {
        return _name;
    }

    /**
     * @dev See {IERC721Metadata-symbol}.
     */
    function symbol() public view virtual override returns (string memory) {
        return _symbol;
    }

    /**
     * @dev See {IERC721Metadata-tokenURI}.
     */
    function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
        require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");

        string memory baseURI = _baseURI();
        return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
    }

    /**
     * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
     * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
     * by default, can be overriden in child contracts.
     */
    function _baseURI() internal view virtual returns (string memory) {
        return "";
    }

    /**
     * @dev See {IERC721-approve}.
     */
    function approve(address to, uint256 tokenId) public virtual override {
        address owner = ERC721.ownerOf(tokenId);
        require(to != owner, "ERC721: approval to current owner");

        require(
            _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
            "ERC721: approve caller is not owner nor approved for all"
        );

        _approve(to, tokenId);
    }

    /**
     * @dev See {IERC721-getApproved}.
     */
    function getApproved(uint256 tokenId) public view virtual override returns (address) {
        require(_exists(tokenId), "ERC721: approved query for nonexistent token");

        return _tokenApprovals[tokenId];
    }

    /**
     * @dev See {IERC721-setApprovalForAll}.
     */
    function setApprovalForAll(address operator, bool approved) public virtual override {
        _setApprovalForAll(_msgSender(), operator, approved);
    }

    /**
     * @dev See {IERC721-isApprovedForAll}.
     */
    function isApprovedForAll(address owner, address operator) public view virtual override returns (bool) {
        return _operatorApprovals[owner][operator];
    }

    /**
     * @dev See {IERC721-transferFrom}.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        //solhint-disable-next-line max-line-length
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");

        _transfer(from, to, tokenId);
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) public virtual override {
        safeTransferFrom(from, to, tokenId, "");
    }

    /**
     * @dev See {IERC721-safeTransferFrom}.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) public virtual override {
        require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
        _safeTransfer(from, to, tokenId, _data);
    }

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * `_data` is additional data, it has no specified format and it is sent in call to `to`.
     *
     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
     * implement alternative mechanisms to perform token transfer, such as signature-based.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeTransfer(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _transfer(from, to, tokenId);
        require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
    }

    /**
     * @dev Returns whether `tokenId` exists.
     *
     * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
     *
     * Tokens start existing when they are minted (`_mint`),
     * and stop existing when they are burned (`_burn`).
     */
    function _exists(uint256 tokenId) internal view virtual returns (bool) {
        return _owners[tokenId] != address(0);
    }

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
    }

    /**
     * @dev Safely mints `tokenId` and transfers it to `to`.
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function _safeMint(address to, uint256 tokenId) internal virtual {
        _safeMint(to, tokenId, "");
    }

    /**
     * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
     * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
     */
    function _safeMint(
        address to,
        uint256 tokenId,
        bytes memory _data
    ) internal virtual {
        _mint(to, tokenId);
        require(
            _checkOnERC721Received(address(0), to, tokenId, _data),
            "ERC721: transfer to non ERC721Receiver implementer"
        );
    }

    /**
     * @dev Mints `tokenId` and transfers it to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
     *
     * Requirements:
     *
     * - `tokenId` must not exist.
     * - `to` cannot be the zero address.
     *
     * Emits a {Transfer} event.
     */
    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), "ERC721: mint to the zero address");
        require(!_exists(tokenId), "ERC721: token already minted");

        _beforeTokenTransfer(address(0), to, tokenId);

        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(address(0), to, tokenId);
    }

    /**
     * @dev Destroys `tokenId`.
     * The approval is cleared when the token is burned.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     *
     * Emits a {Transfer} event.
     */
    function _burn(uint256 tokenId) internal virtual {
        address owner = ERC721.ownerOf(tokenId);

        _beforeTokenTransfer(owner, address(0), tokenId);

        // Clear approvals
        _approve(address(0), tokenId);

        _balances[owner] -= 1;
        delete _owners[tokenId];

        emit Transfer(owner, address(0), tokenId);
    }

    /**
     * @dev Transfers `tokenId` from `from` to `to`.
     *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     *
     * Emits a {Transfer} event.
     */
    function _transfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {
        require(ERC721.ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
        require(to != address(0), "ERC721: transfer to the zero address");

        _beforeTokenTransfer(from, to, tokenId);

        // Clear approvals from the previous owner
        _approve(address(0), tokenId);

        _balances[from] -= 1;
        _balances[to] += 1;
        _owners[tokenId] = to;

        emit Transfer(from, to, tokenId);
    }

    /**
     * @dev Approve `to` to operate on `tokenId`
     *
     * Emits a {Approval} event.
     */
    function _approve(address to, uint256 tokenId) internal virtual {
        _tokenApprovals[tokenId] = to;
        emit Approval(ERC721.ownerOf(tokenId), to, tokenId);
    }

    /**
     * @dev Approve `operator` to operate on all of `owner` tokens
     *
     * Emits a {ApprovalForAll} event.
     */
    function _setApprovalForAll(
        address owner,
        address operator,
        bool approved
    ) internal virtual {
        require(owner != operator, "ERC721: approve to caller");
        _operatorApprovals[owner][operator] = approved;
        emit ApprovalForAll(owner, operator, approved);
    }

    /**
     * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
     * The call is not executed if the target address is not a contract.
     *
     * @param from address representing the previous owner of the given token ID
     * @param to target address that will receive the tokens
     * @param tokenId uint256 ID of the token to be transferred
     * @param _data bytes optional data to send along with the call
     * @return bool whether the call correctly returned the expected magic value
     */
    function _checkOnERC721Received(
        address from,
        address to,
        uint256 tokenId,
        bytes memory _data
    ) private returns (bool) {
        if (to.isContract()) {
            try IERC721Receiver(to).onERC721Received(_msgSender(), from, tokenId, _data) returns (bytes4 retval) {
                return retval == IERC721Receiver.onERC721Received.selector;
            } catch (bytes memory reason) {
                if (reason.length == 0) {
                    revert("ERC721: transfer to non ERC721Receiver implementer");
                } else {
                    assembly {
                        revert(add(32, reason), mload(reason))
                    }
                }
            }
        } else {
            return true;
        }
    }

    /**
     * @dev Hook that is called before any token transfer. This includes minting
     * and burning.
     *
     * Calling conditions:
     *
     * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
     * transferred to `to`.
     * - When `from` is zero, `tokenId` will be minted for `to`.
     * - When `to` is zero, ``from``'s `tokenId` will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId
    ) internal virtual {}
}

// File: @openzeppelin/contracts/utils/math/SafeMath.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/math/SafeMath.sol)

pragma solidity ^0.8.0;

// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.

/**
 * @dev Wrappers over Solidity's arithmetic operations.
 *
 * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
 * now has built in overflow checking.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            uint256 c = a + b;
            if (c < a) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b > a) return (false, 0);
            return (true, a - b);
        }
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
            // benefit is lost if 'b' is also tested.
            // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
            if (a == 0) return (true, 0);
            uint256 c = a * b;
            if (c / a != b) return (false, 0);
            return (true, c);
        }
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a / b);
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        unchecked {
            if (b == 0) return (false, 0);
            return (true, a % b);
        }
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        return a * b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator.
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b <= a, errorMessage);
            return a - b;
        }
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a / b;
        }
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        unchecked {
            require(b > 0, errorMessage);
            return a % b;
        }
    }
}

// File: @openzeppelin/contracts/security/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}

// File: @openzeppelin/contracts/access/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}

// File: hardhat/console.sol



// SPDX-License-Identifier: MIT
pragma solidity >= 0.4.22 <0.9.0;

library console {
	address constant CONSOLE_ADDRESS = address(0x000000000000000000636F6e736F6c652e6c6f67);

	function _sendLogPayload(bytes memory payload) private view {
		uint256 payloadLength = payload.length;
		address consoleAddress = CONSOLE_ADDRESS;
		assembly {
			let payloadStart := add(payload, 32)
			let r := staticcall(gas(), consoleAddress, payloadStart, payloadLength, 0, 0)
		}
	}

	function log() internal view {
		_sendLogPayload(abi.encodeWithSignature("log()"));
	}

	function logInt(int p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(int)", p0));
	}

	function logUint(uint p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint)", p0));
	}

	function logString(string memory p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string)", p0));
	}

	function logBool(bool p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool)", p0));
	}

	function logAddress(address p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address)", p0));
	}

	function logBytes(bytes memory p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes)", p0));
	}

	function logBytes1(bytes1 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes1)", p0));
	}

	function logBytes2(bytes2 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes2)", p0));
	}

	function logBytes3(bytes3 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes3)", p0));
	}

	function logBytes4(bytes4 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes4)", p0));
	}

	function logBytes5(bytes5 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes5)", p0));
	}

	function logBytes6(bytes6 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes6)", p0));
	}

	function logBytes7(bytes7 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes7)", p0));
	}

	function logBytes8(bytes8 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes8)", p0));
	}

	function logBytes9(bytes9 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes9)", p0));
	}

	function logBytes10(bytes10 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes10)", p0));
	}

	function logBytes11(bytes11 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes11)", p0));
	}

	function logBytes12(bytes12 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes12)", p0));
	}

	function logBytes13(bytes13 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes13)", p0));
	}

	function logBytes14(bytes14 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes14)", p0));
	}

	function logBytes15(bytes15 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes15)", p0));
	}

	function logBytes16(bytes16 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes16)", p0));
	}

	function logBytes17(bytes17 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes17)", p0));
	}

	function logBytes18(bytes18 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes18)", p0));
	}

	function logBytes19(bytes19 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes19)", p0));
	}

	function logBytes20(bytes20 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes20)", p0));
	}

	function logBytes21(bytes21 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes21)", p0));
	}

	function logBytes22(bytes22 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes22)", p0));
	}

	function logBytes23(bytes23 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes23)", p0));
	}

	function logBytes24(bytes24 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes24)", p0));
	}

	function logBytes25(bytes25 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes25)", p0));
	}

	function logBytes26(bytes26 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes26)", p0));
	}

	function logBytes27(bytes27 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes27)", p0));
	}

	function logBytes28(bytes28 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes28)", p0));
	}

	function logBytes29(bytes29 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes29)", p0));
	}

	function logBytes30(bytes30 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes30)", p0));
	}

	function logBytes31(bytes31 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes31)", p0));
	}

	function logBytes32(bytes32 p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bytes32)", p0));
	}

	function log(uint p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint)", p0));
	}

	function log(string memory p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string)", p0));
	}

	function log(bool p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool)", p0));
	}

	function log(address p0) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address)", p0));
	}

	function log(uint p0, uint p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint)", p0, p1));
	}

	function log(uint p0, string memory p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string)", p0, p1));
	}

	function log(uint p0, bool p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool)", p0, p1));
	}

	function log(uint p0, address p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address)", p0, p1));
	}

	function log(string memory p0, uint p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint)", p0, p1));
	}

	function log(string memory p0, string memory p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string)", p0, p1));
	}

	function log(string memory p0, bool p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool)", p0, p1));
	}

	function log(string memory p0, address p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address)", p0, p1));
	}

	function log(bool p0, uint p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint)", p0, p1));
	}

	function log(bool p0, string memory p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string)", p0, p1));
	}

	function log(bool p0, bool p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool)", p0, p1));
	}

	function log(bool p0, address p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address)", p0, p1));
	}

	function log(address p0, uint p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint)", p0, p1));
	}

	function log(address p0, string memory p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string)", p0, p1));
	}

	function log(address p0, bool p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool)", p0, p1));
	}

	function log(address p0, address p1) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address)", p0, p1));
	}

	function log(uint p0, uint p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,uint)", p0, p1, p2));
	}

	function log(uint p0, uint p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,string)", p0, p1, p2));
	}

	function log(uint p0, uint p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,bool)", p0, p1, p2));
	}

	function log(uint p0, uint p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,address)", p0, p1, p2));
	}

	function log(uint p0, string memory p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,uint)", p0, p1, p2));
	}

	function log(uint p0, string memory p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,string)", p0, p1, p2));
	}

	function log(uint p0, string memory p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,bool)", p0, p1, p2));
	}

	function log(uint p0, string memory p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,address)", p0, p1, p2));
	}

	function log(uint p0, bool p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,uint)", p0, p1, p2));
	}

	function log(uint p0, bool p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,string)", p0, p1, p2));
	}

	function log(uint p0, bool p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,bool)", p0, p1, p2));
	}

	function log(uint p0, bool p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,address)", p0, p1, p2));
	}

	function log(uint p0, address p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,uint)", p0, p1, p2));
	}

	function log(uint p0, address p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,string)", p0, p1, p2));
	}

	function log(uint p0, address p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,bool)", p0, p1, p2));
	}

	function log(uint p0, address p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,address)", p0, p1, p2));
	}

	function log(string memory p0, uint p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,uint)", p0, p1, p2));
	}

	function log(string memory p0, uint p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,string)", p0, p1, p2));
	}

	function log(string memory p0, uint p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,bool)", p0, p1, p2));
	}

	function log(string memory p0, uint p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,address)", p0, p1, p2));
	}

	function log(string memory p0, string memory p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,uint)", p0, p1, p2));
	}

	function log(string memory p0, string memory p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,string)", p0, p1, p2));
	}

	function log(string memory p0, string memory p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,bool)", p0, p1, p2));
	}

	function log(string memory p0, string memory p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,address)", p0, p1, p2));
	}

	function log(string memory p0, bool p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,uint)", p0, p1, p2));
	}

	function log(string memory p0, bool p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,string)", p0, p1, p2));
	}

	function log(string memory p0, bool p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,bool)", p0, p1, p2));
	}

	function log(string memory p0, bool p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,address)", p0, p1, p2));
	}

	function log(string memory p0, address p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,uint)", p0, p1, p2));
	}

	function log(string memory p0, address p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,string)", p0, p1, p2));
	}

	function log(string memory p0, address p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,bool)", p0, p1, p2));
	}

	function log(string memory p0, address p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,address)", p0, p1, p2));
	}

	function log(bool p0, uint p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,uint)", p0, p1, p2));
	}

	function log(bool p0, uint p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,string)", p0, p1, p2));
	}

	function log(bool p0, uint p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,bool)", p0, p1, p2));
	}

	function log(bool p0, uint p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,address)", p0, p1, p2));
	}

	function log(bool p0, string memory p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,uint)", p0, p1, p2));
	}

	function log(bool p0, string memory p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,string)", p0, p1, p2));
	}

	function log(bool p0, string memory p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,bool)", p0, p1, p2));
	}

	function log(bool p0, string memory p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,address)", p0, p1, p2));
	}

	function log(bool p0, bool p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,uint)", p0, p1, p2));
	}

	function log(bool p0, bool p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,string)", p0, p1, p2));
	}

	function log(bool p0, bool p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,bool)", p0, p1, p2));
	}

	function log(bool p0, bool p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,address)", p0, p1, p2));
	}

	function log(bool p0, address p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,uint)", p0, p1, p2));
	}

	function log(bool p0, address p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,string)", p0, p1, p2));
	}

	function log(bool p0, address p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,bool)", p0, p1, p2));
	}

	function log(bool p0, address p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,address)", p0, p1, p2));
	}

	function log(address p0, uint p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,uint)", p0, p1, p2));
	}

	function log(address p0, uint p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,string)", p0, p1, p2));
	}

	function log(address p0, uint p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,bool)", p0, p1, p2));
	}

	function log(address p0, uint p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,address)", p0, p1, p2));
	}

	function log(address p0, string memory p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,uint)", p0, p1, p2));
	}

	function log(address p0, string memory p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,string)", p0, p1, p2));
	}

	function log(address p0, string memory p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,bool)", p0, p1, p2));
	}

	function log(address p0, string memory p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,address)", p0, p1, p2));
	}

	function log(address p0, bool p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,uint)", p0, p1, p2));
	}

	function log(address p0, bool p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,string)", p0, p1, p2));
	}

	function log(address p0, bool p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,bool)", p0, p1, p2));
	}

	function log(address p0, bool p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,address)", p0, p1, p2));
	}

	function log(address p0, address p1, uint p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,uint)", p0, p1, p2));
	}

	function log(address p0, address p1, string memory p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,string)", p0, p1, p2));
	}

	function log(address p0, address p1, bool p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,bool)", p0, p1, p2));
	}

	function log(address p0, address p1, address p2) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,address)", p0, p1, p2));
	}

	function log(uint p0, uint p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,uint,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,uint,string)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,uint,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,uint,address)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,string,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,string,string)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,string,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,string,address)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,bool,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,bool,string)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,bool,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,bool,address)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,address,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,address,string)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,address,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, uint p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,uint,address,address)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,uint,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,uint,string)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,uint,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,uint,address)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,string,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,string,string)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,string,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,string,address)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,bool,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,bool,string)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,bool,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,bool,address)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,address,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,address,string)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,address,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, string memory p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,string,address,address)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,uint,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,uint,string)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,uint,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,uint,address)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,string,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,string,string)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,string,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,string,address)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,bool,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,bool,string)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,bool,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,bool,address)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,address,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,address,string)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,address,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, bool p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,bool,address,address)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,uint,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,uint,string)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,uint,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,uint,address)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,string,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,string,string)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,string,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,string,address)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,bool,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,bool,string)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,bool,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,bool,address)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,address,uint)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,address,string)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,address,bool)", p0, p1, p2, p3));
	}

	function log(uint p0, address p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(uint,address,address,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,uint,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,uint,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,uint,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,uint,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,string,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,string,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,string,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,string,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,bool,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,bool,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,bool,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,bool,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,address,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,address,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,address,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, uint p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,uint,address,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,uint,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,uint,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,uint,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,uint,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,string,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,string,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,string,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,string,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,bool,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,bool,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,bool,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,bool,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,address,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,address,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,address,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, string memory p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,string,address,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,uint,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,uint,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,uint,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,uint,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,string,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,string,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,string,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,string,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,bool,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,bool,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,bool,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,bool,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,address,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,address,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,address,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, bool p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,bool,address,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,uint,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,uint,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,uint,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,uint,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,string,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,string,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,string,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,string,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,bool,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,bool,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,bool,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,bool,address)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,address,uint)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,address,string)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,address,bool)", p0, p1, p2, p3));
	}

	function log(string memory p0, address p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(string,address,address,address)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,uint,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,uint,string)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,uint,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,uint,address)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,string,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,string,string)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,string,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,string,address)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,bool,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,bool,string)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,bool,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,bool,address)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,address,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,address,string)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,address,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, uint p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,uint,address,address)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,uint,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,uint,string)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,uint,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,uint,address)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,string,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,string,string)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,string,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,string,address)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,bool,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,bool,string)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,bool,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,bool,address)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,address,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,address,string)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,address,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, string memory p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,string,address,address)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,uint,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,uint,string)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,uint,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,uint,address)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,string,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,string,string)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,string,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,string,address)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,bool,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,bool,string)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,bool,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,bool,address)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,address,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,address,string)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,address,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, bool p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,bool,address,address)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,uint,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,uint,string)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,uint,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,uint,address)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,string,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,string,string)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,string,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,string,address)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,bool,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,bool,string)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,bool,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,bool,address)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,address,uint)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,address,string)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,address,bool)", p0, p1, p2, p3));
	}

	function log(bool p0, address p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(bool,address,address,address)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,uint,uint)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,uint,string)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,uint,bool)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,uint,address)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,string,uint)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,string,string)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,string,bool)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,string,address)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,bool,uint)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,bool,string)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,bool,bool)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,bool,address)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,address,uint)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,address,string)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,address,bool)", p0, p1, p2, p3));
	}

	function log(address p0, uint p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,uint,address,address)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,uint,uint)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,uint,string)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,uint,bool)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,uint,address)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,string,uint)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,string,string)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,string,bool)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,string,address)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,bool,uint)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,bool,string)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,bool,bool)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,bool,address)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,address,uint)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,address,string)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,address,bool)", p0, p1, p2, p3));
	}

	function log(address p0, string memory p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,string,address,address)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,uint,uint)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,uint,string)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,uint,bool)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,uint,address)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,string,uint)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,string,string)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,string,bool)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,string,address)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,bool,uint)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,bool,string)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,bool,bool)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,bool,address)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,address,uint)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,address,string)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,address,bool)", p0, p1, p2, p3));
	}

	function log(address p0, bool p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,bool,address,address)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, uint p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,uint,uint)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, uint p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,uint,string)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, uint p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,uint,bool)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, uint p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,uint,address)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, string memory p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,string,uint)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, string memory p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,string,string)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, string memory p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,string,bool)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, string memory p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,string,address)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, bool p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,bool,uint)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, bool p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,bool,string)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, bool p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,bool,bool)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, bool p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,bool,address)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, address p2, uint p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,address,uint)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, address p2, string memory p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,address,string)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, address p2, bool p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,address,bool)", p0, p1, p2, p3));
	}

	function log(address p0, address p1, address p2, address p3) internal view {
		_sendLogPayload(abi.encodeWithSignature("log(address,address,address,address)", p0, p1, p2, p3));
	}

}

// File: contracts/RewardVault.sol




// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;


/**
 * @title RewardVault
 * @dev RewardVault is a token holder contract that will only allow 
 * a farm to withdraw and deposit. This keeps rewards separate from user
 * deposits, removes the need to mint reward tokens and gives a clear indication
 * of the state of a farm / pool.
 */


import '@openzeppelin/contracts/access/Ownable.sol';
import '@openzeppelin/contracts/utils/math/SafeMath.sol';
import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/token/ERC20/ERC20.sol';
import '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";


contract RewardVault is Ownable, ReentrancyGuard {
  using SafeMath for uint256;
  using SafeERC20 for ERC20;
  // IBEP20 basic reward token being held
  IERC20 public rewardToken;

  // authorized users
  mapping (address => bool) authorizedAddresses;

  receive() external payable {
  }

  constructor(IERC20 _rewardToken) {
    rewardToken = _rewardToken;
    // Steps: Deploy this, Deploy farm point at this.
    // then configure this to authorize farm address.
    authorizedAddresses[owner()] = true;
  }

  function setAuthorizedAddress(address _addr, bool isAuthorized) public {
    require(authorizedAddresses[msg.sender] == true, "unauthorized");
    authorizedAddresses[_addr] = isAuthorized;
  }

  function sendReward(address recipient, uint256 amount) public nonReentrant{
    require(authorizedAddresses[msg.sender] == true, 'unauthorized');
    rewardToken.transfer(recipient, amount);
  }

  function withdrawResidual(IERC20 token) public {
    require(authorizedAddresses[msg.sender] == true, 'unauthorized');
    payable(msg.sender).transfer(address(this).balance);
    token.transfer(msg.sender,token.balanceOf(address(this)));
  }
}
// File: contracts/IFarmV3.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

interface IFarmV3 {
    struct PoolInfo {
        uint256 origTotSupply; // supply of rewards tokens put up to be rewarded by original owner
        uint256 curRewardsSupply; // current supply of rewards
        uint256 totalTokensStaked; // current amount of tokens staked
        uint256 creationBlock; // block this contract was created
        uint256 perBlockNum; // amount of rewards tokens rewarded per block
        uint256 lastRewardBlock; // Prev block where distribution updated (ie staking/unstaking updates this)
        uint256 accERC20PerShare; // Accumulated ERC20s per share, times 1e36.
        uint256 stakeTimeLockSec; // number of seconds after depositing the user is required to stake before unstaking
    }

    struct StakerInfo {
        uint256 blockOriginallyStaked; // block the user originally staked
        uint256 timeOriginallyStaked; // unix timestamp in seconds that the user originally staked
        uint256 blockLastHarvested; // the block the user last claimed/harvested rewards
        uint256 rewardDebt; // Reward debt. See explanation below.
    }

    function pool() external view returns (PoolInfo memory);

    function stakers(address user) external view returns (StakerInfo memory);

    function balanceOf(address user) external view returns (uint256 balance);

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    function unstakeTokens(
        uint256 _amount,
        bool shouldHarvest
    ) external payable;
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

// File: @openzeppelin/contracts/token/ERC721/IERC721.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

import "../../utils/introspection/IERC165.sol";

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address from,
        address to,
        uint256 tokenId
    ) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool _approved) external;

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(
        address from,
        address to,
        uint256 tokenId,
        bytes calldata data
    ) external;
}

// File: @openzeppelin/contracts/token/ERC721/IERC721Receiver.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/IERC721Receiver.sol)

pragma solidity ^0.8.0;

/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
interface IERC721Receiver {
    /**
     * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
     * by `operator` from `from`, this function is called.
     *
     * It must return its Solidity selector to confirm the token transfer.
     * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
     *
     * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
     */
    function onERC721Received(
        address operator,
        address from,
        uint256 tokenId,
        bytes calldata data
    ) external returns (bytes4);
}

// File: @openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC721.sol";

/**
 * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
interface IERC721Metadata is IERC721 {
    /**
     * @dev Returns the token collection name.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the token collection symbol.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
     */
    function tokenURI(uint256 tokenId) external view returns (string memory);
}

// File: @openzeppelin/contracts/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

// File: @openzeppelin/contracts/utils/Strings.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Strings.sol)

pragma solidity ^0.8.0;

/**
 * @dev String operations.
 */
library Strings {
    bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";

    /**
     * @dev Converts a `uint256` to its ASCII `string` decimal representation.
     */
    function toString(uint256 value) internal pure returns (string memory) {
        // Inspired by OraclizeAPI's implementation - MIT licence
        // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol

        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }
        return string(buffer);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
     */
    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return "0x00";
        }
        uint256 temp = value;
        uint256 length = 0;
        while (temp != 0) {
            length++;
            temp >>= 8;
        }
        return toHexString(value, length);
    }

    /**
     * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
     */
    function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = "0";
        buffer[1] = "x";
        for (uint256 i = 2 * length + 1; i > 1; --i) {
            buffer[i] = _HEX_SYMBOLS[value & 0xf];
            value >>= 4;
        }
        require(value == 0, "Strings: hex length insufficient");
        return string(buffer);
    }
}

// File: @openzeppelin/contracts/utils/introspection/ERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// File: @openzeppelin/contracts/utils/introspection/IERC165.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}

// File: @openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";
import "../../../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}