不多废话，直接上代码

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

int main() {
long long n, m;
cin >> n >> m;
long long sum = 0;

for (int k = 1; k <= min(n, m); ++k) {
    sum += (n - k + 1) * (m - k + 1);
}

cout << sum << endl;
return 0;

}