I can't find the reason why I'm getting "Bummer" sign on this

using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {
            int intNum = 0;
            bool gotNumber = false;
            while(!gotNumber){
              try{
                Console.Write("Enter the number of times to print \"Yay!\": ");
                string stgNum = Console.ReadLine();
                intNum = int.Parse(stgNum);
                gotNumber = true;
              }catch (FormatException){
                Console.Write("You must enter a whole number.\n");
              }catch (ArgumentNullException){
                Console.Write("You must enter a whole number.\n");
              }
            }
            int i=0;
            while(i < intNum)
            {
              Console.Write("\"Yay\"");
              i += 1;
            }

        }
    }
}