using System;

public class Program

{

    public static double Factorial(int number)

    {

        if ( number == 0)

            return 1;

        double factorial = 1;

        for(int i = number; i >= 1; i --)

        {

            factorial = factorial * i;

        }

        return factorial;

    }

    public static void Main()

    {

        Console.WriteLine( " Enter Number: ");

        int number = Convert.ToInt32(Console.ReadLine());

        double factorial = Factorial(number);

        Console.WriteLine("Factorial of {0} is {1}" ,number, factorial);

    }

}