package no500;

import java.util.Scanner;

public class Main {
	public static long MOD = 1000000000000L;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		n = Math.min(n, 1000);
		long fact = 1;
		boolean of = false;
		long fact2 = 1;
		for(int i=1;i<=n;i++) {
			fact = fact * i % MOD;
			fact2 = fact * i;
			if (fact2 >= MOD) {
				of = true;
			}
		}
//		if (of) {
//			System.out.println(String.format("%012d", fact));
//		}else{
			System.out.println(fact);
//		}
		
	}
}