using System;
using System.Numerics;
class Program
{
    static ulong fact(ulong x)
    {
        if (x == 0)
            return 1;
        else
            return x * fact(x - 1);
    }
    static void Main()
    {
        ulong[] Numbers = Array.ConvertAll(Console.ReadLine().Split(' '), r => ulong.Parse(r));
        Console.WriteLine(fact(Numbers[0] | Numbers[1]));
    }
}