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

using ll = long long;
const int INF = 1e9;
const ll inf = 1LL<<60;

int main() {
  ll a, b; cin >> a >> b;
  ll p = a | b;
  ll ans = 1;
  for (ll i=2; i<=p; i++) ans *= i;
  cout << ans << endl;
}