using System;

public class Program

{

    public static void Main()

    {

       int result= Factorial(5);

       Console.WriteLine(result);

       Console.WriteLine("Hello World");

    }

​

​

     static int Factorial (int num){

        if (num == 0)

            return 1;

         else 

             return num * Factorial(num-1);

      }

}