import java.util.*;

public class Main {
    static final long MOD = 1000000000000L;
 	public static void main (String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		if (n < 100 && kaijo(n) != 0) {
		    System.out.println(kaijo(n));
		} else {
		    System.out.println("000000000000");
		}
	}
	
	static long kaijo (long x) {
	    if (x <= 1) {
	        return 1;
	    } else {
	        return x * kaijo(x - 1) %  MOD;
	    }
	}
}