using System;

static public class Program

{

    public static int fact(int x)

    {

        if (x==1)

            return 1;

        else return fact(x-1)*x;

    }

    public static void Main()

    {

    Console.WriteLine("Enter the no to find factorial");

        int x=int.Parse(Console.ReadLine());

        int y=fact(x);

        Console.WriteLine("Factorial of {0} is {1}",x,y);

    }

}