import java.util.Scanner;
public class Kaijocalc {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner s = new Scanner(System.in);
		long N = s.nextLong();
		long ans = 1;
		StringBuilder str = new StringBuilder();
		s.close();
		long t = (long)Math.pow(10, 12);
		for(int i = 1;i <= N;i++){
			ans *= i;
			if(ans > t){
				str.append(ans);
				str.delete(0, str.length()-12);
				ans %= t;
			}else{
				str.delete(0, str.length());
				str.append(ans);
			}
			if(ans == 0){
				str = new StringBuilder("0");
				break;
			}
		}
		
		System.out.println(str);

	}

}