using System;

public class Program

{

    public static void Main()

    {

            Console.WriteLine("Please enter a number");

            ulong n;

            double n;

            string whatever = Console.ReadLine();

        if(ulong.TryParse(whatever, out n))

           {Console.WriteLine("Congrats you follwed instructions.");

           }

           else

           {Console.WriteLine("Boo, you didn't follow instruction.");

           }

}}