#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using P = pair<int, int>;
using mint = modint1000000007;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

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