uint BinaryTreeHeightDef(Node currentNode)

        {

            if (currentNode == null) return 0;

            Node node = currentNode;

            uint h1 = 0, h2 = 0;

            if (currentNode.Left != null)

            {

                h1 = BinaryTreeHeightDef(currentNode.Left);

            }

            if (currentNode.Right != null)

            {

                h2 = BinaryTreeHeightDef(currentNode.Left);

            }

            return (Math.Max(h1, h2) + 1);

        }