using System;

using System.Collections.Generic;

public class Program

{

    private class Node

    {

        public string Name;

        public List<Node> Children = new List<Node>();

    }

    public static void Main()

    {

        var root = new Node { Name = "root" };

        Console.WriteLine("Creating tree");

        CreateTree(root);

        Console.WriteLine("Calculating descendent count");

        Console.WriteLine(CalculateDescendents(root));

    }

    private static void CreateTree(Node node, int level = 1, int maxDepth = 10)

    {

        if (level >= maxDepth)

        {

            return;

        }

        var random = new Random();

        var childrenCount = random.Next(1, 10);

        for (var i = 0; i < childrenCount; i++)

        {

            var child = new Node { Name = string.Format("Level {0}, Child {1}", level, i) };

            node.Children.Add(child);

            CreateTree(child, level + 1);

        }

    }

    private static int CalculateDescendents(Node node)

    {

        if (node.Children.Count == 0)

        {

            return 0;

        }

        var totalChildCount = 0;

        foreach (var child in node.Children)

        {

            totalChildCount += 1 +  CalculateDescendents(child);

        }

        return totalChildCount;

    }

}