Find the longest zigzag from a binary tree

BinaryTreeFindLongestZigZag.cs

class Tree
{
    public int x;
    public Tree l;
    public Tree r;
};

class Task3
{
    public int solution(Tree T)
    {
        return FindZigZag(T, 0) - 1;
    }

    int FindZigZag(Tree t, int max)
    {
        if (t == null) return 0;

        int lh = Count(t, true, 0);
        int rh = Count(t, false, 0);

        max = Math.Max(lh, rh);
        max = Math.Max(max, FindZigZag(t.l, max));
        max = Math.Max(max, FindZigZag(t.r, max));

        return max;
    }

    int Count(Tree node, bool moveLeft, int count)
    {
        if (node == null) return count;

        count = moveLeft
            ? Count(node.l, !moveLeft, node.l == null ? count : count + 1)
            : Count(node.r, !moveLeft, node.r == null ? count : count + 1);

        return count;
    }         
}

well... stats for the solution above:
correctness: 0%
performance: 25%
total: 12% out of 100%