// Write a function that takes the tree represented as “sons” array and

// returns the length (=number of edges) of the longest possible path

// from the root to a leaf (this number is called the height of the tree).

using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        int[][] sons = new int[5][];

        sons[0] = new int[] { 1, 2 };

        sons[1] = new int[] { };

        sons[2] = new int[] { 3 };

        sons[3] = new int[] { 4 };

        sons[4] = new int[] { };

        Console.WriteLine("Depth={0}", Depth(sons, 0));

    }

    public static int Depth(int [][] sons, int node)

    {

        int depth = 0;

        foreach(int child in sons[node])

        {

            depth = Math.Max(depth, 1 + Depth(sons, child));

        }

        return depth;

    }

}