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

contract PolkadotCTF {
    address public winner;

    event FlagCaptured(address indexed player);

    // Encoded parts of the flag as byte arrays
    bytes private part1 = hex"50437b497354686973";
    bytes private part2 = hex"546865466c61674f72";
    bytes private part3 = hex"644e6f747d";

    // Function to decode the parts and get the full flag
    function decodeFlag() public view returns (string memory) {
        return string(abi.encodePacked(part1, part2, part3));
    }

    // Function to capture the flag
    function captureFlag(string memory _solution) public {
        string memory decodedFlag = decodeFlag();
        require(keccak256(abi.encodePacked(_solution)) == keccak256(abi.encodePacked(decodedFlag)), "Incorrect solution");
        winner = msg.sender;
        emit FlagCaptured(msg.sender);
    }

    // Function to get the flag
    function getFlag() public view returns (string memory) {
        require(msg.sender == winner, "You are not the winner");
        return decodeFlag();
    }
}