#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll k, t; cin >> k >> t;
    ll x, y, z = 1;
    y = x = k|t;
    for(ll i = 1; i <= x; i++){
        z *= y;
        y--;
    }
    cout << z << '\n';
    return 0;
}