#include <bits/stdc++.h>
#define rep(i, l, r) for (int i = (l); i < (r); i++)
using namespace std;

typedef long long ll;

int main() {
    int A, B;
    cin >> A >> B;
    int C = A | B;
    ll ans = 1;
    rep(i, 0, C) ans *= i + 1;
    cout << ans << endl;
}