import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		sc.close();

		int c = a | b;
		long ans = 1;
		for (int i = 1; i <= c; i++) {
			ans *= i;
		}
		System.out.println(ans);
	}
}