Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: MIT   
//                                                                                                                                                                                                                                                           
//           ..                                                                                        
//          !57       ^.                                                                                 
//      .:?PB&BPP5J: :75!77?777~^:.        .....     :: .                   .   .....:^~~!!!~:..        
//      ~J###&PYPBY ^5B#GPB##BP5J!.   .~?5G##BPY:    ^?Y5      .::..      ..7. .7PBB#&#&&@&&&G7^.       
//      :J#GG#!  :.  J#BJ7~~^^^^::: ^?P&@##BBP5G?    .5G#!.:^7YG##5^      ?5G^  .!7?Y#&?^^::::.         
//       ^Y&&#^     .JBB:          :P#B&Y7!!~^:.      ?&#GYG#@@#Y~.       J@@!      ^#@!                 
//        .?#@5:    ^P#&P555YYJ~:  ^GP#J              ?@&&#G5?^.          ?@&!      ~#@7             
//         .5&&#7   7GGG5YYYJJ?!.  :GG#J.             J#&BPGJ^.           J&&~      J@#^                
//        7#B!#&7  7PGP:           ?#&Y~.           .?B#GGB&&BJ~.        ~B&^     .G#B^            
//     ^^::Y&#J#&P..JB&P:           .5B&5J~          .?#@P.!5GPBBP?.      J&#.     ~GBB.          
//    :YB#B&@#P57: :G&G~             :?G&#B5YY5JJ?.  :P&#5   :^JG&#P^     P#P      !PG5         
//     .^^^5B!      75Y:              .^7GBB&###G?^  :JP7^      :!^??.   ^JJ^      ^?!.         
//         :~:      .:                   .^!?J?YY~.    !.       
//
//                            $FCKIT ~ https://twitter.com/FCKITCOIN
//                             Contract developed by @shrimpyuk :^)                         


pragma solidity ^0.8.9;

import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract FCKIT is Ownable, ERC20 {
    bool isDeployed = false;                        //If the contract is deployed
    bool public isLimited;                  //Enabled to deter Token Hoarding + MEV Sniping during our launch. Limits slowly raised then dropped to ensure smooth and fair release.
    uint256 public maxHoldAmount;           //Maximum Balance to be able to trade in Limited Trading Phase. Used to deter Token Hoarding + MEV Sniping during our launch.
    uint256 public minHoldAmount;           //Minimum Balance to be able to trade in Limited Trading Phase. Used to deter Token Hoarding + MEV Sniping during our launch.
    address public liqudityPoolSwapPair;    //Address of our initial Liquidity Pool

    mapping(address => bool) public hasFuckedAround; //Blacklisted Address Map. Fuck Around => Find Out
    
    uint256 public constant SUPPLY_CAP = 42_690_000_000 * 1 ether; //42,690,000,000 supply cap

    //Important Wallets
    address constant cexReserveWallet = 0xCdA13fE7AEa02AD5740E3Fd48913A24b83976C60; 
    address constant managementWallet = 0x5346ffCc2291A9d555E8B860A263B94338E043be;

    // Supply Distribution:
    // 10%      Team Allocation
    uint constant teamAllocation = ((SUPPLY_CAP / 1000)*100); //10%
    // 22.5%    Liquidity Pool
    uint constant liquidityPoolAllocation = ((SUPPLY_CAP / 1000)*225); //22.5%
    // 10%      Developments Reserve
    // Used for CEX Liquidity + Emergency Use
    uint constant cexReserveAllocation = ((SUPPLY_CAP / 1000)*250); //25%
    // 0.2%     Airdrop (Freebies)
    uint constant airdropAllocation = ((SUPPLY_CAP / 1000)*2); //0.2%
    // 42.3%    Presale Allocation
    uint constant presaleAllocation = ((SUPPLY_CAP / 1000)*423); //42.3%

    // Wallets for locking funds
    address[4] public lockedWallets;
    uint256[4] public walletAllocations;

    uint256 public LOCK_DURATION = 14 days;

    // Team Wallets
    address constant teamWallet1 = 0xF3bb77973f7F1de2fC99fCAE3AF66b56e5df5114;
    address constant teamWallet2 = 0xc4AAeE79cC0a7c5d4EC3F4f8279f31Ba15055e6B;
    address constant teamWallet3 = 0x3a1c2AA33BC5522D59cF729e701C31cc4B8F0037;
    address constant teamWallet4 = 0xff955eFf3d270D44B39D228F7ECdfe41aD5760B3;

    constructor() ERC20("FCKIT", "FCKIT") {
        // Mint tokens to gnosis safes
        _mint(cexReserveWallet, cexReserveAllocation);
        _mint(managementWallet, liquidityPoolAllocation+airdropAllocation+presaleAllocation);

        // Assign Team Allocations
        walletAllocations[0] = ((teamAllocation / 100) * 50); // 50% of team allocation for wallet 1
        walletAllocations[1] = ((teamAllocation / 100) * 20); // 20% of team allocation for wallet 2
        walletAllocations[2] = ((teamAllocation / 100) * 20); // 20% of team allocation for wallet 3
        walletAllocations[3] = ((teamAllocation / 100) * 10); // 10% of team allocation for wallet 4

        // Lock Wallets
        lockedWallets[0] = teamWallet1;
        lockedWallets[1] = teamWallet2;
        lockedWallets[2] = teamWallet3;
        lockedWallets[3] = teamWallet4;

        // Mint 10% of Team's Allocation
        for (uint i = 0; i < walletAllocations.length; i++) {
            uint256 allocation = walletAllocations[i];
            uint256 initial = allocation / 10;
            walletAllocations[i] = allocation - initial;
            _mint(lockedWallets[i], initial);
        }
        
        // Apply 14 Day Lock to remainder 90% of Team's Allocation
        setLockDuration(block.timestamp + (14 days));

        isDeployed = true;
        _transferOwnership(managementWallet);
    }

    // Sets the lock duration of funds. Can only be called internally and once, via the initializer.
    function setLockDuration(uint256 duration) internal {
        require(!isDeployed, "Lock duration can only be set before deployment");
        LOCK_DURATION = duration;
    }

    // @notice Withdraw Team's Allocation after 14 Day Lock
    function withdrawLockedFunds() external {
        require(block.timestamp >= LOCK_DURATION, "Funds are still locked");
        for (uint i = 0; i < lockedWallets.length; i++) {
            address wallet = lockedWallets[i];
            uint256 allocation = walletAllocations[i];
            if (allocation > 0) {
                walletAllocations[i] = 0;
                _mint(wallet, allocation);
            }
        }
    }

    /// @notice Blacklist/Unblacklist a Wallet
    /// @param _address The Address of the wallet to modify
    /// @param _hasFuckedAround If they are blacklisted or not
    function foundOut(address _address, bool _hasFuckedAround) external onlyOwner {
        hasFuckedAround[_address] = _hasFuckedAround;
    }

    /// @notice Set temporary trading rules to ensure a smooth launch detering token hoarding + MEV sniping.
    /// @param _isLimited If the temporary trading rules should apply
    /// @param _tokenSwapPair Address of the Token Swap Pair e.g. Uniswap
    /// @param _maxHoldAmount Maximum amount of tokens that can be held to interact with the Liquduity Pool during the limited phase
    /// @param _minHoldAmount Minimum amount of tokens that can be held to interact with the Liquduity Pool during the limited phase
    function setRules(bool _isLimited, address _tokenSwapPair, uint256 _maxHoldAmount, uint256 _minHoldAmount) external onlyOwner {
        isLimited = _isLimited;
        liqudityPoolSwapPair = _tokenSwapPair;
        maxHoldAmount = _maxHoldAmount;
        minHoldAmount = _minHoldAmount;
    }

    /// @notice Set them tokens on fire
    /// @param value How many tokens to burn
    function burn(uint256 value) external {
        _burn(msg.sender, value);
    }

     //Enforce Ruleset
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 amount
    ) override internal virtual {
        // Blacklist Ruleset
        require(!hasFuckedAround[to] && !hasFuckedAround[from], "Fucked Around & Found Out");

        // Exclude Pre-Liqudity Trading (Aside from Owner Wallet)
        if (liqudityPoolSwapPair == address(0) && isDeployed) {
            require(from == owner() || to == owner(), "Trading has not yet started");
            return;
        }

        //Extra rules to keep a fair and smooth release :)
        if (isLimited && from == liqudityPoolSwapPair) {
            require(super.balanceOf(to) + amount <= maxHoldAmount && super.balanceOf(to) + amount >= minHoldAmount, "Forbidden");
        }
    }
}

// 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;
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling 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);
    }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * 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}.
     *
     * 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 default value returned by this function, unless
     * it's 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;
            // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
            // decrementing then incrementing.
            _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;
        unchecked {
            // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
            _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;
            // Overflow not possible: amount <= accountBalance <= totalSupply.
            _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 {}
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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);
}

// 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);
}