Do not know how to do the last task of the challenge.

using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {
            Console.Write("Enter the number of times to print \"Yay!\": ");

             try
                 {
                     var number = Int32.Parse(Console.ReadLine());

                       for(var i = 0; i < number; i++)
                             {
                                    Console.WriteLine("Yay!");
                             }   
                 }
            catch(FormatException)
                {

                    Console.WriteLine("You must enter a whole number.");

                }

            }


    }
}