u8

import java.util.Scanner;

public class u8 {
    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        int n = Integer.parseInt(scanner.nextLine());
        int fakt = 1;

        for (int i = 1; i <= n; i++) {
        fakt = fakt*i;
        continue;
            }
        System.out.println(fakt);

        }
    }