public class Node
        {
            public enum NodeType { sum, minus, divison, multiplication, number};
            public NodeType ntype;
            public Node left;
            public Node right;
            public int value;
            public Node(Node l, Node r, NodeType n, int num)
            {
                left = l;
                right = r;
                ntype = n;
                value = num;
            }
            
            public void print(Node n, int offset)
            {

                for (int i = 0; i < offset; i++)
                    Console.Write(" ");

                string s = "+-/*";
                if (n.ntype == NodeType.number)
                    Console.WriteLine(n.value);
                else
                    Console.WriteLine(s[(int)(n.ntype)]);

                if (n.left != null)
                    print(n.left, offset + 4);

                if (n.right != null)
                    print(n.right, offset + 4);

            }
            Node res = new Node(new Node(
                                         new Node(null, null, Node.NodeType.number, 5), 
                                         new Node(null, null, Node.NodeType.number, 2), 
                                         Node.NodeType.sum, 
                                         0), 
                                new Node(null, null, Node.NodeType.number, 3), 
                                Node.NodeType.multiplication, 
                                0);
            res.print(res, 0);
            Console.Read();