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contracts...FungibleToken.sol

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.0;

import "hardhat/console.sol";

import "https://raw.githubusercontent.com/OpenZeppelin/openzeppelin-contracts/master/contracts/token/ERC20/ERC20.sol";

contract FungibleToken is ERC20 {
    constructor(uint256 totalSupply) ERC20("MyBestToken", "BTKN") {
        _mint(msg.sender, totalSupply);
    }

    function burn(uint256 burnAmount) external {
        _burn(msg.sender, burnAmount);
    }

    function mint(uint256 amount) external {
        _mint(msg.sender, amount);
    }
}