codee

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

contract DeadmansSwitch {
    address public owner;
    address public presetAddress;
    uint256 public lastAliveBlock;

    modifier onlyOwner() {
        require(msg.sender == owner, "Not the contract owner");
        _;
    }

    constructor(address _presetAddress) {
        owner = msg.sender;
        presetAddress = _presetAddress;
        lastAliveBlock = block.number;
    }

    function still_alive() external onlyOwner {
        lastAliveBlock = block.number;
    }

    function checkAlive() external {
        require(block.number - lastAliveBlock <= 10, "Owner not alive");
        _selfDestruct();
    }

    function _selfDestruct() internal {
        selfdestruct(presetAddress);
    }
}