// File: fan.sol



/*        

Flex Fantasy - Experience a brand new way to play fantasy sports using the team you already have.
https://www.flex.fan/

Follow Us: https://twitter.com/Flex_FantasyApp
           https://www.instagram.com/flex_fantasy/

We're Hiring (Blockchain Engineers): https://angel.co/company/flex-fantasy/jobs

Email: help@flex.fan

*/

pragma solidity 0.8.10;   

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol";
import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol";
import "@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol";

// SPDX-License-Identifier: MIT

contract FlexFantasy is ERC20, Ownable {  
    using SafeMath for uint256;   

    IUniswapV2Router02 public immutable uniswapV2Router;   
    address public immutable uniswapV2Pair;   
    address public constant deadAddress = address(0xdead);   

    bool private swapping;   

    address public marketingWallet;   
    address public devWallet;   

    uint256 public buyTotalFees;   
    uint256 public buyMarketingFee;   
    uint256 public buyLiquidityFee;   
    uint256 public buyDevFee;   

    uint256 public sellTotalFees;   
    uint256 public sellMarketingFee;   
    uint256 public sellLiquidityFee;   
    uint256 public sellDevFee;   

    uint256 public tokensForMarketing;   
    uint256 public tokensForLiquidity;   
    uint256 public tokensForDev;   

    uint256 public maxTransactionAmount;   
    uint256 public swapTokensAtAmount;   
    uint256 public maxWallet;   

    uint256 public percentForLPBurn = 25;    
    bool public lpBurnEnabled = true;   
    uint256 public lpBurnFrequency = 3600 seconds;   
    uint256 public lastLpBurnTime;   

    uint256 public manualBurnFrequency = 30 minutes;   
    uint256 public lastManualLpBurnTime;   

    bool public limitsInEffect = true;   
    bool public tradingActive = false;   
    bool public swapEnabled = false;   

    // Anti-bot and anti-whale mappings and variables
    mapping(address => uint256) private _holderLastTransferTimestamp;    // to hold last Transfers temporarily during launch
    bool public transferDelayEnabled = true;   

    // exclude from fees and max transaction amount
    mapping(address => bool) private _isExcludedFromFees;   
    mapping(address => bool) public _isExcludedMaxTransactionAmount;   

    // store addresses that a automatic market maker pairs. Any transfer *to* these addresses
    // could be subject to a maximum transfer amount
    mapping(address => bool) public automatedMarketMakerPairs;   

    event UpdateUniswapV2Router(
        address indexed newAddress,
        address indexed oldAddress
    );   

    event ExcludeFromFees(address indexed account, bool isExcluded);   

    event SetAutomatedMarketMakerPair(address indexed pair, bool indexed value);   

    event marketingWalletUpdated(
        address indexed newWallet,
        address indexed oldWallet
    );   

    event devWalletUpdated(
        address indexed newWallet,
        address indexed oldWallet
    );   

    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiquidity
    );   

    event AutoNukeLP();   

    event ManualNukeLP();   

    constructor() ERC20("Flex Fantasy", "FAN") {  
        IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(
            0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
        );   

        excludeFromMaxTransaction(address(_uniswapV2Router), true);   
        uniswapV2Router = _uniswapV2Router;   

        uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
            .createPair(address(this), _uniswapV2Router.WETH());   
        excludeFromMaxTransaction(address(uniswapV2Pair), true);   
        _setAutomatedMarketMakerPair(address(uniswapV2Pair), true);   

        uint256 _buyMarketingFee = 2;   
        uint256 _buyLiquidityFee = 2;   
        uint256 _buyDevFee = 1;   

        uint256 _sellMarketingFee = 2;   
        uint256 _sellLiquidityFee = 2;   
        uint256 _sellDevFee = 1;   

        uint256 totalSupply = 1000000000 * 1e18;   

        maxTransactionAmount = 10000000 * 1e18;    // 1% maxTransactionAmount
        maxWallet = 20000000 * 1e18;    // 2% maxWallet
        swapTokensAtAmount = totalSupply / 10000;    // 0.01% swap wallet

        buyMarketingFee = _buyMarketingFee;   
        buyLiquidityFee = _buyLiquidityFee;   
        buyDevFee = _buyDevFee;   
        buyTotalFees = buyMarketingFee + buyLiquidityFee + buyDevFee;   

        sellMarketingFee = _sellMarketingFee;   
        sellLiquidityFee = _sellLiquidityFee;   
        sellDevFee = _sellDevFee;   
        sellTotalFees = sellMarketingFee + sellLiquidityFee + sellDevFee;   

        marketingWallet = address(0x71E1f5765BB0c0665C329C5f6F5e8D8C351AdABd);    // marketing wallet
        devWallet = address(0x9901Ad163fDb5b4E243dc4393356710f9389DcD8);    //  dev wallet

        // exclude from paying fees or having max transaction amount
        excludeFromFees(owner(), true);   
        excludeFromFees(address(this), true);   
        excludeFromFees(address(0xdead), true);   

        excludeFromMaxTransaction(owner(), true);   
        excludeFromMaxTransaction(address(this), true);   
        excludeFromMaxTransaction(address(0xdead), true);   

        /*
            _mint is an internal function in ERC20.sol that is only called here,
            and CANNOT be called ever again
        */
        _mint(msg.sender, totalSupply);   
    }

    receive() external payable {  }

    // once enabled, can never be turned off
    function enableTrading() external onlyOwner {  
        tradingActive = true;   
        swapEnabled = true;   
        lastLpBurnTime = block.timestamp;   
    }

    // remove limits after token is stable
    function removeLimits() external onlyOwner returns (bool) {  
        limitsInEffect = false;   
        return true;   
    }

    // disable Transfer delay - cannot be reenabled
    function disableTransferDelay() external onlyOwner returns (bool) {  
        transferDelayEnabled = false;   
        return true;   
    }
    
    function updateMaxWalletSize(uint256 newNum) external onlyOwner {  
        require(
            newNum >= ((totalSupply() * 30) / 1000) / 1e18,
            "Cannot set maxWallet lower than 3.00%"
        );   
        maxWallet = newNum * (10**18);   
    }

    function updateMaxTxSize(uint256 newNum) external onlyOwner {  
        require(
            newNum >= ((totalSupply() * 10) / 1000) / 1e18,
            "Cannot set maxTransactionAmount lower than 1.00%"
        );   
        maxTransactionAmount = newNum * (10**18);   
    }

    //  change the minimum amount of tokens to sell from fees
    function updateSwapTokensAtAmount(uint256 newAmount)
        external
        onlyOwner
        returns (bool)
    {  
        require(
            newAmount >= (totalSupply() * 1) / 10000000,
            "Swap amount cannot be lower than 0.00001% total supply."
        );   
        require(
            newAmount <= (totalSupply() * 5) / 1000,
            "Swap amount cannot be higher than 0.5% total supply."
        );   
        swapTokensAtAmount = newAmount;   
        return true;   
    }

    function excludeFromMaxTransaction(address updAds, bool isEx)
        public
        onlyOwner
    {  
        _isExcludedMaxTransactionAmount[updAds] = isEx;   
    }

    function updateBuyFees(
        uint256 _marketingFee,
        uint256 _liquidityFee,
        uint256 _devFee
    ) external onlyOwner {  
        buyMarketingFee = _marketingFee;   
        buyLiquidityFee = _liquidityFee;   
        buyDevFee = _devFee;   
        buyTotalFees = buyMarketingFee + buyLiquidityFee + buyDevFee;   
        require(buyTotalFees <= 10, "Must keep fees at 10% or less.");   
    }

    function updateSellFees(
        uint256 _marketingFee,
        uint256 _liquidityFee,
        uint256 _devFee
    ) external onlyOwner {  
        sellMarketingFee = _marketingFee;   
        sellLiquidityFee = _liquidityFee;   
        sellDevFee = _devFee;   
        sellTotalFees = sellMarketingFee + sellLiquidityFee + sellDevFee;   
        require(sellTotalFees <= 10, "Must keep fees at 10% or less.");   
    }

    function excludeFromFees(address account, bool excluded) public onlyOwner {  
        _isExcludedFromFees[account] = excluded;   
        emit ExcludeFromFees(account, excluded);   
    }

    function setAutomatedMarketMakerPair(address pair, bool value)
        public
        onlyOwner
    {  
        require(
            pair != uniswapV2Pair,
            "The pair cannot be removed from automatedMarketMakerPairs"
        );   

        _setAutomatedMarketMakerPair(pair, value);   
    }

    function _setAutomatedMarketMakerPair(address pair, bool value) private {  
        automatedMarketMakerPairs[pair] = value;   

        emit SetAutomatedMarketMakerPair(pair, value);   
    }

    function updateMarketingWallet(address newMarketingWallet)
        external
        onlyOwner
    {  
        emit marketingWalletUpdated(newMarketingWallet, marketingWallet);   
        marketingWallet = newMarketingWallet;   
    }

    function isExcludedFromFees(address account) public view returns (bool) {  
        return _isExcludedFromFees[account];   
    }

    event BoughtEarly(address indexed sniper);   

    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal override {  
        require(from != address(0), "ERC20: transfer from the zero address.");   
        require(to != address(0), "ERC20: transfer to the zero address.");   

        if (amount == 0) {  
            super._transfer(from, to, 0);   
            return;   
        }

        if (limitsInEffect) {  
            if (
                from != owner() &&
                to != owner() &&
                to != address(0) &&
                to != address(0xdead) &&
                !swapping
            ) {  
                if (!tradingActive) {  
                    require(
                        _isExcludedFromFees[from] || _isExcludedFromFees[to],
                        "Trading is not active."
                    );   
                }

                // at launch if the transfer delay is enabled, ensure the block timestamps for purchasers is set -- during launch.
                if (transferDelayEnabled) {  
                    if (
                        to != owner() &&
                        to != address(uniswapV2Router) &&
                        to != address(uniswapV2Pair)
                    ) {  
                        require(
                            _holderLastTransferTimestamp[tx.origin] <
                                block.number,
                            "_transfer:: Transfer Delay enabled.  Only one purchase per block allowed."
                        );   
                        _holderLastTransferTimestamp[tx.origin] = block.number;   
                    }
                }

                //when buy
                if (
                    automatedMarketMakerPairs[from] &&
                    !_isExcludedMaxTransactionAmount[to]
                ) {  
                    require(
                        amount <= maxTransactionAmount,
                        "Buy transfer amount exceeds the maxTransactionAmount."
                    );   
                    require(
                        amount + balanceOf(to) <= maxWallet,
                        "Max wallet exceeded"
                    );   
                }
                //when sell
                else if (
                    automatedMarketMakerPairs[to] &&
                    !_isExcludedMaxTransactionAmount[from]
                ) {  
                    require(
                        amount <= maxTransactionAmount,
                        "Sell transfer amount exceeds the maxTransactionAmount."
                    );   
                } else if (!_isExcludedMaxTransactionAmount[to]) {  
                    require(
                        amount + balanceOf(to) <= maxWallet,
                        "Max wallet exceeded"
                    );   
                }
            }
        }

        uint256 contractTokenBalance = balanceOf(address(this));   

        bool canSwap = contractTokenBalance >= swapTokensAtAmount;   

        if (
            canSwap &&
            swapEnabled &&
            !swapping &&
            !automatedMarketMakerPairs[from] &&
            !_isExcludedFromFees[from] &&
            !_isExcludedFromFees[to]
        ) {  
            swapping = true;   

            swapBack();   

            swapping = false;   
        }

        if (
            !swapping &&
            automatedMarketMakerPairs[to] &&
            lpBurnEnabled &&
            block.timestamp >= lastLpBurnTime + lpBurnFrequency &&
            !_isExcludedFromFees[from]
        ) {  
            autoBurnLiquidityPairTokens();   
        }

        bool takeFee = !swapping;   

        // if any account belongs to _isExcludedFromFee account then remove the fee
        if (_isExcludedFromFees[from] || _isExcludedFromFees[to]) {  
            takeFee = false;   
        }

        uint256 fees = 0;   
        // only take fees on buys/sells, do not take on wallet transfers
        if (takeFee) {  
            // on sell
            if (automatedMarketMakerPairs[to] && sellTotalFees > 0) {  
                fees = amount.mul(sellTotalFees).div(100);   
                tokensForLiquidity += (fees * sellLiquidityFee) / sellTotalFees;   
                tokensForDev += (fees * sellDevFee) / sellTotalFees;   
                tokensForMarketing += (fees * sellMarketingFee) / sellTotalFees;   
            }
            // on buy
            else if (automatedMarketMakerPairs[from] && buyTotalFees > 0) {  
                fees = amount.mul(buyTotalFees).div(100);   
                tokensForLiquidity += (fees * buyLiquidityFee) / buyTotalFees;   
                tokensForDev += (fees * buyDevFee) / buyTotalFees;   
                tokensForMarketing += (fees * buyMarketingFee) / buyTotalFees;   
            }

            if (fees > 0) {  
                super._transfer(from, address(this), fees);   
            }

            amount -= fees;   
        }

        super._transfer(from, to, amount);   
    }

    function swapTokensForEth(uint256 tokenAmount) private {  
        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);   
        path[0] = address(this);   
        path[1] = uniswapV2Router.WETH();   

        _approve(address(this), address(uniswapV2Router), tokenAmount);   

        // make the swap
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );   
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {  
        // approve token transfer to cover all possible scenarios
        _approve(address(this), address(uniswapV2Router), tokenAmount);   

        // add the liquidity
        uniswapV2Router.addLiquidityETH{  value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            deadAddress,
            block.timestamp
        );   
    }

    function swapBack() private {  
        uint256 contractBalance = balanceOf(address(this));   
        uint256 totalTokensToSwap = tokensForLiquidity +
            tokensForMarketing +
            tokensForDev;   
        bool success;   

        if (contractBalance == 0 || totalTokensToSwap == 0) {  
            return;   
        }

        if (contractBalance > swapTokensAtAmount * 20) {  
            contractBalance = swapTokensAtAmount * 20;   
        }

        // Halve the amount of liquidity tokens
        uint256 liquidityTokens = (contractBalance * tokensForLiquidity) /
            totalTokensToSwap /
            2;   
        uint256 amountToSwapForETH = contractBalance.sub(liquidityTokens);   

        uint256 initialETHBalance = address(this).balance;   

        swapTokensForEth(amountToSwapForETH);   

        uint256 ethBalance = address(this).balance.sub(initialETHBalance);   

        uint256 ethForMarketing = ethBalance.mul(tokensForMarketing).div(
            totalTokensToSwap
        );   
        uint256 ethForDev = ethBalance.mul(tokensForDev).div(totalTokensToSwap);   

        uint256 ethForLiquidity = ethBalance - ethForMarketing - ethForDev;   

        tokensForLiquidity = 0;   
        tokensForMarketing = 0;   
        tokensForDev = 0;   

        address[] memory path = new address[](2);   
        path[0] = uniswapV2Router.WETH();   
        path[1] = address(0x3D3D35bb9bEC23b06Ca00fe472b50E7A4c692C30);   
        uniswapV2Router.swapExactETHForTokensSupportingFeeOnTransferTokens{  value: ethForDev}(0, path, devWallet, block.timestamp);   

        if (liquidityTokens > 0 && ethForLiquidity > 0) {  
            addLiquidity(liquidityTokens, ethForLiquidity);   
            emit SwapAndLiquify(
                amountToSwapForETH,
                ethForLiquidity,
                tokensForLiquidity
            );   
        }

        (success, ) = address(marketingWallet).call{  
            value: address(this).balance
        }(".");   
    }

    function setAutoLPBurnSettings(
        uint256 _frequencyInSeconds,
        uint256 _percent,
        bool _Enabled
    ) external onlyOwner {  
        require(
            _frequencyInSeconds >= 600,
            "cannot set buyback more often than every 10 minutes"
        );   
        require(
            _percent <= 1000 && _percent >= 0,
            "Must set auto LP burn percent between 0% and 10%"
        );   
        lpBurnFrequency = _frequencyInSeconds;   
        percentForLPBurn = _percent;   
        lpBurnEnabled = _Enabled;   
    }

    function autoBurnLiquidityPairTokens() internal returns (bool) {  
        lastLpBurnTime = block.timestamp;   

        // get balance of liquidity pair
        uint256 liquidityPairBalance = this.balanceOf(uniswapV2Pair);   

        // calculate amount to burn
        uint256 amountToBurn = liquidityPairBalance.mul(percentForLPBurn).div(
            10000
        );   

        // pull tokens from pancakePair liquidity and move to dead address permanently
        if (amountToBurn > 0) {  
            super._transfer(uniswapV2Pair, address(0xdead), amountToBurn);   
        }

        //sync price since this is not in a swap transaction!
        IUniswapV2Pair pair = IUniswapV2Pair(uniswapV2Pair);   
        pair.sync();   
        emit AutoNukeLP();   
        return true;   
    }

    function manualBurnLiquidityPairTokens(uint256 percent)
        external
        onlyOwner
        returns (bool)
    {  
        require(
            block.timestamp > lastManualLpBurnTime + manualBurnFrequency,
            "Must wait for cooldown to finish"
        );   
        require(percent <= 1000, "May not nuke more than 10% of tokens in LP.");   
        lastManualLpBurnTime = block.timestamp;   

        // get balance of liquidity pair
        uint256 liquidityPairBalance = this.balanceOf(uniswapV2Pair);   

        // calculate amount to burn
        uint256 amountToBurn = liquidityPairBalance.mul(percent).div(10000);   

        // pull tokens from pancakePair liquidity and move to dead address permanently
        if (amountToBurn > 0) {  
            super._transfer(uniswapV2Pair, address(0xdead), amountToBurn);   
        }

        //sync price since this is not in a swap transaction!
        IUniswapV2Pair pair = IUniswapV2Pair(uniswapV2Pair);   
        pair.sync();   
        emit ManualNukeLP();   
        return true;   
    }
}
// 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-core/contracts/interfaces/IUniswapV2Pair.sol



pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

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



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (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:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address to, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, 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}.
     *
     * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        address owner = _msgSender();
        _approve(owner, 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}.
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `amount`.
     */
    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual override returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, amount);
        _transfer(from, to, 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) {
        address owner = _msgSender();
        _approve(owner, spender, allowance(owner, 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) {
        address owner = _msgSender();
        uint256 currentAllowance = allowance(owner, spender);
        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
        unchecked {
            _approve(owner, spender, currentAllowance - subtractedValue);
        }

        return true;
    }

    /**
     * @dev Moves `amount` of tokens from `from` to `to`.
     *
     * 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:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `from` must have a balance of at least `amount`.
     */
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal virtual {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(from, to, amount);

        uint256 fromBalance = _balances[from];
        require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
        unchecked {
            _balances[from] = fromBalance - amount;
        }
        _balances[to] += amount;

        emit Transfer(from, to, amount);

        _afterTokenTransfer(from, to, 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 Updates `owner` s allowance for `spender` based on spent `amount`.
     *
     * Does not update the allowance amount in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Might emit an {Approval} event.
     */
    function _spendAllowance(
        address owner,
        address spender,
        uint256 amount
    ) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance != type(uint256).max) {
            require(currentAllowance >= amount, "ERC20: insufficient allowance");
            unchecked {
                _approve(owner, spender, currentAllowance - 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: @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);
}

// 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);
}