#include <bits/stdc++.h>
using namespace std;
int main(){
	int a, b;
	cin >> a >> b;
	auto f = [&](double x){
		return x * x * x / 3 - (a + b) * x * x / 2 + a * b * x;
	};
	cout << abs(f(a) - f(b)) << endl;
}