O(min(a, b))

#include <iostream>
using namespace std;

int a, b, ans;

int main() {
    cin >> a >> b;

    for (int i = 1; i <= min(a, b); i++) {
        ans += (a - i + 1) * (b - i + 1);
    }
    cout << ans;
    return 0;
}