// 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 (last updated v4.7.0) (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 Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }

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

    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        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: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

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

// 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/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: contracts/SmokeToken.sol



// SPDX-License-Identifier: Unlicensed
pragma solidity ^0.8.9;

import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol";
import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";


contract SmokeToken is Ownable, IERC20Metadata {
    using SafeMath for uint256; // this safemath relies on solidity's built in overflow checks

    uint8 constant _decimals = 18;

    uint256 _totalSupply = 100000000 * (10**_decimals); // 100 mill
    uint256 public _maxTxAmount = (_totalSupply * 2) / 100; // 2 mill default

    uint256 public _walletMax = (_totalSupply * 2) / 100;

    address DEAD_WALLET = 0x000000000000000000000000000000000000dEaD;
    address ZERO_WALLET = 0x0000000000000000000000000000000000000000;

    address routerAddress; // uniswap v2 router

    string constant _name = "Smoke Protocol Token";
    string constant _symbol = "$SMOKE";

    bool public restrictWhales = true;

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

    mapping(address => bool) public isFeeExempt;
    mapping(address => bool) public isTxLimitExempt;

    uint256 public liquidityFee = 30; // 0.3% in bips
    uint256 public sessionsFee = 167; //  1.67% default sessions wallet fee
    uint256 public devFee = 333; //3.33% default developer wallet fee

    uint256 public totalFee = 500;
    uint256 public totalFeeIfSelling = 1000;  //10% in bips

    address private autoLiquidityReceiver;
    address private sessionsWallet;
    address private devWallet;

    IUniswapV2Router02 public router;
    address public pair;

    uint256 public launchedAt;
    bool public tradingOpen = true;
    bool public blacklistMode = true;
    mapping(address => bool) public isBlacklisted;
    mapping(address => bool) public isInternal;
    mapping(address => bool) internal authorizations;

    bool inSwapAndLiquify;
    bool public swapAndLiquifyEnabled = true;
    bool public swapAndLiquifyByLimitOnly = false;
    bool checkOn = false;

    // wallet threshold limit, changeable
    uint256 public swapThreshold = _totalSupply / 5000; //20k default

    event AutoLiquify(uint256 amountETH, uint256 amountBOG);
    event SwapAndLiquifyEnabledUpdated(bool enabled);

    modifier lockTheSwap() {
        inSwapAndLiquify = true;
        _;
        inSwapAndLiquify = false;
    }

    constructor(
        address _routerAddress,
        address _devWallet,
        address _sessionsWallet
    ) {
        routerAddress = _routerAddress;
        devWallet = _devWallet;
        sessionsWallet = _sessionsWallet;
        router = IUniswapV2Router02(routerAddress);
        pair = IUniswapV2Factory(router.factory()).createPair(router.WETH(), address(this));
        _allowances[address(this)][address(router)] = type(uint256).max;
        _allowances[address(this)][address(pair)] = type(uint256).max;

        isFeeExempt[msg.sender] = true;
        isFeeExempt[address(this)] = true;
        isFeeExempt[DEAD_WALLET] = true;

        authorizations[owner()] = true;
        isInternal[address(this)] = true;
        isInternal[msg.sender] = true;
        isInternal[address(pair)] = true;
        isInternal[address(router)] = true;

        isTxLimitExempt[msg.sender] = true;
        isTxLimitExempt[pair] = true;
        isTxLimitExempt[DEAD_WALLET] = true;

        autoLiquidityReceiver = address(0);

        isFeeExempt[sessionsWallet] = true;
        isFeeExempt[devWallet] = true;
        totalFee = liquidityFee.add(sessionsFee).add(devFee);
        totalFeeIfSelling = totalFeeIfSelling.add(liquidityFee);

        _balances[msg.sender] = _totalSupply;
        emit Transfer(address(0), msg.sender, _totalSupply);
    }

    receive() external payable {}

    function name() external pure override returns (string memory) {
        return _name;
    }

    function symbol() external pure override returns (string memory) {
        return _symbol;
    }

    function decimals() external pure override returns (uint8) {
        return _decimals;
    }

    function totalSupply() external view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function allowance(address holder, address spender) external view override returns (uint256) {
        return _allowances[holder][spender];
    }

    function getCirculatingSupply() public view returns (uint256) {
        return _totalSupply.sub(balanceOf(DEAD_WALLET)).sub(balanceOf(ZERO_WALLET));
    }

    function approve(address spender, uint256 amount) public override returns (bool) {
        _allowances[msg.sender][spender] = amount; // approve from holder(msg.sender) to spender to spend this amount
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function approveMax(address spender) external returns (bool) {
        return approve(spender, type(uint256).max);
    }

    function launched() internal view returns (bool) {
        return launchedAt != 0;
    }

    function launch() internal {
        launchedAt = block.number;
    }

    function checkTxLimit(address sender, uint256 amount) internal view {
        require(amount <= _maxTxAmount || isTxLimitExempt[sender], "TX Limit Exceeded");
    }

    function transfer(address recipient, uint256 amount) external override returns (bool) {
        return _transferFrom(msg.sender, recipient, amount);
    }

    function _basicTransfer(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        _balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function setBridge(address bridge) public onlyOwner {
        authorizations[bridge] = true;
        isFeeExempt[bridge] = true;
        isTxLimitExempt[bridge] = true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external override returns (bool) {
        if (_allowances[sender][msg.sender] != type(uint256).max) {
            _allowances[sender][msg.sender] = _allowances[sender][msg.sender].sub(
                amount,
                "Insufficient Allowance"
            );
        }
        return _transferFrom(sender, recipient, amount);
    }

    function _transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (bool) {
        if (inSwapAndLiquify) {
            return _basicTransfer(sender, recipient, amount);
        }
        if (!authorizations[sender] && !authorizations[recipient]) {
            require(tradingOpen, "Trading not open yet");
        }

        require(amount <= _maxTxAmount || isTxLimitExempt[sender], "TX Limit Exceeded");
        if (
            msg.sender != pair &&
            !inSwapAndLiquify &&
            swapAndLiquifyEnabled &&
            _balances[address(this)] >= swapThreshold
        ) {
            marketingAndLiquidity();
        }
        if (!launched() && recipient == pair) {
            require(_balances[sender] > 0, "Zero balance violated!");
            launch();
        }

        if (checkOn) {
            checkBot(sender, recipient);
        }

        // Blacklist
        if (blacklistMode) {
            require(!isBlacklisted[sender], "Blacklisted");
        }

        //Exchange tokens
        _balances[sender] = _balances[sender].sub(amount, "Insufficient Balance");

        if (!isTxLimitExempt[recipient] && restrictWhales) {
            require(_balances[recipient].add(amount) <= _walletMax, "Max wallet violated!");
        }

        uint256 finalAmount = !isFeeExempt[sender] && !isFeeExempt[recipient]
            ? extractFee(sender, recipient, amount)
            : amount;
        _balances[recipient] = _balances[recipient].add(finalAmount);

        emit Transfer(sender, recipient, finalAmount);
        return true;
    }

    function extractFee(
        address sender,
        address recipient,
        uint256 amount
    ) internal returns (uint256) {
        uint256 feeApplicable = pair == recipient ? totalFeeIfSelling : totalFee;
        uint256 feeAmount = amount.mul(feeApplicable).div(10_000); //fee in bips so divide by 10k

        _balances[address(this)] = _balances[address(this)].add(feeAmount);
        emit Transfer(sender, address(this), feeAmount);

        return amount.sub(feeAmount);
    }

    function marketingAndLiquidity() internal lockTheSwap {
        uint256 tokensToLiquify = _balances[address(this)];

        uint256 sessionF = 3330;
        uint256 devF = 6660;
        uint256 feeEmbersement = sessionF + devF + liquidityFee; // 33.4% + 66.6% + 0.3%

        uint256 amountToLiquify = tokensToLiquify.mul(liquidityFee).div(feeEmbersement).div(2);
        uint256 amountToSwap = tokensToLiquify.sub(amountToLiquify);

        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = router.WETH();

        router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            amountToSwap,
            0,
            path,
            address(this),
            block.timestamp
        );

        uint256 amountETH = address(this).balance;

        uint256 totalETHFee = feeEmbersement.sub(liquidityFee.div(2)); // also half LP fee in ETH 0.15%

        uint256 amountETHLiquidity = amountETH.mul(liquidityFee).div(totalETHFee).div(2);
        uint256 amountETHSessions = amountETH.mul(sessionF).div(totalETHFee);
        uint256 amountETHDev = amountETH.mul(devF).div(totalETHFee);
        //gas 30000
        (bool tmpSuccess1, ) = payable(sessionsWallet).call{value: amountETHSessions}("");
        tmpSuccess1 = false;

        (bool tmpSuccess2, ) = payable(devWallet).call{value: amountETHDev}("");
        tmpSuccess2 = false;

        // burning LP tokens to remove a proportional share of the underlying reserves.
        if (amountToLiquify > 0) {
            router.addLiquidityETH{value: amountETHLiquidity}(
                address(this),
                amountToLiquify,
                0,
                0,
                autoLiquidityReceiver,
                block.timestamp
            );
            emit AutoLiquify(amountETHLiquidity, amountToLiquify);
        }
    }

    function checkBot(address sender, address recipient) internal {
        if (
            (isCont(recipient) && !isInternal[recipient] && !isFeeExempt[recipient] && checkOn) ||
            (sender == pair && !isInternal[sender] && msg.sender != tx.origin && checkOn)
        ) {
            isBlacklisted[recipient] = true;
        }
    }

    function isCont(address addr) internal view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(addr)
        }
        return size > 0;
    }

    // CONTRACT OWNER FUNCTIONS
    function setisInternal(bool _bool, address _address) external onlyOwner {
        isInternal[_address] = _bool;
    }

    function setMode(bool _bool) external onlyOwner {
        checkOn = _bool;
    }

    function setWalletLimit(uint256 newLimit) external onlyOwner {
        _walletMax = newLimit;
    }

    function setTransactionLimit(uint256 newLimit) external onlyOwner {
        _maxTxAmount = newLimit;
    }

    function tradingStatus(bool newStatus) public onlyOwner {
        tradingOpen = newStatus;
    }

    function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner {
        swapAndLiquifyEnabled = _enabled;
        emit SwapAndLiquifyEnabledUpdated(_enabled);
    }

    function setIsAuthorized(address _address, bool isAuth) external onlyOwner {
        authorizations[_address] = isAuth;
    }

    function setIsFeeExempt(address holder, bool exempt) external onlyOwner {
        isFeeExempt[holder] = exempt;
    }

    function setIsTxLimitExempt(address holder, bool exempt) external onlyOwner {
        isTxLimitExempt[holder] = exempt;
    }

    /**
     * @dev fees should be set in bips aka basis points 1% == 100 bips
     * @param newLiqFee = default 0.3% set as 30
     * @param newsessionsFee = default 1.67% as 167
     * @param newDevFee = default 3.33% set as 333
     * @param extraSellFee = default 5% extra, total 10% in sell
     */
    function setFees(
        uint256 newLiqFee,
        uint256 newsessionsFee,
        uint256 newDevFee,
        uint256 extraSellFee
    ) external onlyOwner {
        liquidityFee = newLiqFee;
        sessionsFee = newsessionsFee;
        devFee = newDevFee;

        totalFee = liquidityFee.add(sessionsFee).add(devFee);
        totalFeeIfSelling = totalFee + extraSellFee;
    }

    function setSwapThreshold(uint256 _newSwapThreshold) public onlyOwner {
        swapThreshold = _newSwapThreshold;
    }

    function enable_blacklist(bool _status) public onlyOwner {
        blacklistMode = _status;
    }

    function manage_blacklist(address[] calldata addresses, bool status) public onlyOwner {
        for (uint256 i; i < addresses.length; ++i) {
            isBlacklisted[addresses[i]] = status;
        }
    }

    function rescueToken(address tokenAddress, uint256 tokens)
        public
        onlyOwner
        returns (bool success)
    {
        return IERC20Metadata(tokenAddress).transfer(msg.sender, tokens);
    }

    function clearStuckBalance(uint256 amountPercentage) external onlyOwner {
        uint256 amountETH = address(this).balance;
        payable(msg.sender).transfer((amountETH * amountPercentage) / 100);
    }

    /** Getters */

    /** Setters */

    // change the developer wallet that receives developer tax benifits
    function setDeveloperWallet(address _newDevWallet) public onlyOwner {
        devWallet = _newDevWallet;
    }

    // change the marketing wallet that receives marketing tax benifits
    function setSessionsWallet(address _newSessionsWallet) public onlyOwner {
        sessionsWallet = _newSessionsWallet;
    }
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (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 subtraction 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: @uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol



pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol



pragma solidity >=0.6.2;

import './IUniswapV2Router01.sol';

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

// File: @uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router01.sol



pragma solidity >=0.6.2;

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}