#include <iostream>
#include <cmath>
#include <iomanip>

using namespace std;

int main() {
	int a, b;
	cin >> a >> b;
	double result = 0;
	for (double x = a; x < b; x += 0.00001) {
		result += abs((x - a) * (x - b) * 0.00001);
	}
	cout << fixed << setprecision(4) << result << endl;
	return 0;
}