#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  double a, b;
  cin >> a >> b;
  auto f = [a, b](double x) { return (x - a) * (x - b); };
  int N = 1000000;
  double res = 0;
  for (double x = a; x < b; x += abs(b - a) / N) {
    res += (b - a) / N * abs(f(x));
  }
  cout << fixed << setprecision(10) << res << '\n';
  return 0;
}