import java.io.*;

class Factorial {


     public static void main(String args[]) {

     int n = new Integer(args[0]).intValue();
     System.out.print(n + "! = ");
     System.out.println(fact(n) + "\n");

     }

     static int fact(int n) {
         int a = 1;
         for (int i = 0; i++ < n; )
            a *= i;
         return a;
     }
}