import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        long Z = 1;
        long mod = (long)Math.pow(10,12);
        for(int i=1; i<=N; i++){
            Z*=i;
            Z%=mod;
            if(Z==0)break;
        }
        System.out.println(Z);
    }
}