pragma solidity ^0.4.15;

contract Node {
    Pyramid public pyramid;
    uint public amount;
    address public owner;
    address public parent;

    function Node(Pyramid _pyramid, address _parent) {
        pyramid = _pyramid;
        owner = msg.sender;
        parent = _parent;
        accrue(1);
    }

    function accrue(uint8 i) {
        if (i <= 5) {
            owner.transfer(pyramid.at(i));
            if (address(0) != parent) {
                Node(parent).accrue(i + 1);
            }
        }
    }
}

contract Pyramid {
    uint[6] public levels;

    function Pyramid(uint[6] marketing) {
        levels = marketing;
    }

    function at(uint i) external returns(uint) {
        return levels[i];
    }

    function enter(address parent) external payable returns (Node) {
        uint diff = msg.value - levels[0];
        require(diff >= 0);
        if (diff > 0) {
            msg.sender.transfer(diff);
        }
        return new Node(this, parent);
    }
}