using System;

public class Program

{

    public static void Main()

    {

        //Dan Jeremeel Fernández González

        int n;

        int total = 1;

        Console.WriteLine("Hi! Write a number and I'll tell you its factorial.");

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

        for (int i = 1; i<=n; i++)

        {

            total = total*i;

        }

        Console.WriteLine(n + "! = " + total);

    }

}