Help me with this one (C#)

Hello help me I'm stuck with this one because you have to use multiple catches and I don't know how to that.

the first task: This final code challenge will require you to use almost everything we've covered in this course. You’ll write a program to celebrate completing this course by printing “Yay!” to the screen a given number of times. Write a program that: Prompts the user to enter the number of times to enter “Yay!”. I've done this for you. Leave this as it is. Prints “Yay!” to the screen that number of times (Hint: You’ll need a loop for this. You’ll also need to keep track of how many times the loop has run). You can print them all on the same line or on separate lines. \passed

the second task was this : Add more input validation to your program by printing “You must enter a positive number.” if the user enters a negative number. \passed

and here is the third one where I don't know what to do: Add more input validation to your program by printing “You must enter a positive number.” if the user enters a negative number.

using System;

namespace Treehouse.CodeChallenges
{
    class Program
    {
        static void Main()
        {
            Console.Write("Enter the number of times to print \"Yay!\": ");
            var entry = Console.ReadLine();
            int counter  = 0;

            try
            {
            var total = int.Parse(entry);
            while (total > counter)
            {
                    Console.WriteLine("Yay!");
                    counter +=1;
            }
            }

            catch(FormatException)
            {
            Console.WriteLine("You must enter a whole number");
            }
            Console.ReadLine();
        }
    }
}