using System;

public class Program

{

     public static void Main()

    {

         int fact, num;

         Console.Write("Enter a number: ");

         num= Convert.ToInt32(Console.ReadLine());  

         Program obj=new Program();

         fact=obj.factorial(num);

         Console.WriteLine("Factorial of {0} is {1}", num, fact);

     }

     public int factorial(int num)

    {

        // termination condition

        if (num == 0)

            return 1;

        else

            // recursive call

            return num * factorial(num - 1);

    }

}