C# Basics, Final Challenge Task 3 throws Exception

using System;

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

                while ( numberOfTimes < 0 )
                {
                    Console.WriteLine("You must enter a positive number.");   
                    Console.Write("Enter the number of times to print \"Yay!\": ");
                    numberOfTimes = int.Parse(Console.ReadLine());
                }

                for (int i = 0; i < numberOfTimes; i++)
                {
                    Console.WriteLine("Yay!");
                }
            }
            catch (FormatException) 
            {
                Console.WriteLine("You must enter a whole number.");
            }
        }
    }
}