using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Console.WriteLine("m?");

        int m = int.Parse(Console.ReadLine());

        Console.WriteLine("n?");

        int n = int.Parse(Console.ReadLine());

​

        Console.WriteLine(string.Format("A({0},{1})", m.ToString(), n.ToString()));

        int result = ffff.A(m,n);

        Console.WriteLine(result.ToString());

        Console.WriteLine(string.Format("calls: {0}", ffff.calls.ToString()));

    }

}

​

public class ffff {

    public static int calls = 0;

    public static int A(int m, int n)

    {

        calls++;

        if (m == 0)

        {

            return n + 1;

        }

        else if (m > 0 && n == 0)

        {

            return A(m - 1, 1);

        }

        else if (m > 0 && n > 0)

        {

            return A(m - 1, A(m, n - 1));

        }

        throw new Exception();

    }

}