void max(Node& root, int& level, int& sum)
{
    level = 0;
    sum = root.getValue();

    std::deque<Node&> current { root };
    std::deque<Node&> next;

    int curLevel = 0;
    int curSum = 0;
    while ( ! current.empty() ) {
        Node& node = current.front();
        current.pop();

        sum += node.getValue();
        std::copy(std::back_inserter(next), node.begin(), node.end());

        if (current.empty())
        {
            if (curSum > sum) {
                sum = curSum;
                level = curLevel;
            }
            curSum = 0;
            ++curLevel;
            std::swap(current, next);
        }
    }
}