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

int main() {
	int h,k,n = 0,g = 0;
	cin >> h >> k;
	//n += h*k;
	while(h-g > 0 && k-g > 0){
		n += (h-g)*(k-g);
		g++;
	}
	cout << n;
	return 0;
}