class BinaryTree
    {

        public Node Root { get; set; }

        public class Node
        {
            public int Data { get; set; }
            public Node Left { get; set; }
            public Node Right { get; set; }

            public Node(int data)
            {
                Data = data;
                Left = null;
                Right = null;
            }
        }

        public void Insert(int data)
        {
            InsertRecursive(data, Root);
        }

        private void InsertRecursive(int data, Node node)
        {
            Node newNode = new Node(data);

            // base case
            // for non root, if you were lead to a null node, t
            // this should be the correct case
            if (node == null)
                node = newNode;

            else
            {
                // if new value > node => go right
                if (data > node.Data)
                    InsertRecursive(data, node.Right);
                // if new value < node => go left
                else if (data < node.Data)
                    InsertRecursive(data, node.Left);

            }
        }
        static void Main(string[] args)
        {
            BinaryTree tree2 = new BinaryTree();
            tree2.Insert(4);
            tree2.Insert(2);
            tree2.Insert(5);
            tree2.Insert(1);
            tree2.Insert(3);
        }

    }

if (node == null)
            Root = newNode;
        else
        {