using System;

public class Program

{

    public static void Main()

    {

        int c, t=1, n=1;

        Console.WriteLine("Input number for factorial value");

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

        while (c>=t)

        {

            n=n*c;

            c=c-1;

        }

        Console.WriteLine("Factorial value is" + n);

    }

}