using System;
public class Program
{
public static Node BuildTree()
var root = new Node() {
Left = new Node() {
Value = "8"
},
Right = new Node() {
Value = "5"
Value = "*"
Value = "2"
Value = "+"
};
return root;
}
public static void Main()
var root = BuildTree();
var result = WriteExp(root);
Console.WriteLine("result: " + result);
public class Node
public Node Left;
public Node Right;
public string Value;
// walk the tree "in-order" and output a concatenated string
public static string WriteExp(Node node)
