#include <iostream>
using namespace std;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    const double N = 10000;
    double a, b; cin >> a >> b;

    auto f = [&](double x) {
        return (x - a) * (x - b);
    };

    double ans = 0;
    double d = (b - a) / N;
    for (int i = 0; i < N; i++) {
        ans += d * f(a + d * i);
    }
    cout << abs(ans) << "\n";
}