Fallout

// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;

import "openzeppelin-contracts-06/math/SafeMath.sol";

contract Fallout {
    using SafeMath for uint256;
    mapping(address => uint256) allocations;
    address payable public owner;

    /* constructor */
    function Fal1out() public payable {
        owner = msg.sender;
        allocations[owner] = msg.value;
    }

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

    function allocate() public payable {
        allocations[msg.sender] = allocations[msg.sender].add(msg.value);
    }

    function collectAllocations() public onlyOwner {
        msg.sender.transfer(address(this).balance);
    }
}