using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        var input = Console.ReadLine().Split().Select(int.Parse).ToArray();
        long ans = Kaijou(input[0] | input[1]);
        Console.WriteLine(ans);
    }

    static long Kaijou(long n)
    {
        if (n == 1) return 1;
        return n * Kaijou(n - 1);
    }
}