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

#define int long long
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }


double aa, bb;

double f(double x){
	return (x-aa)*(x-bb);
}

signed main(){
	int a, b;
	cin >> a >> b;
	aa = a;
	bb = b;

	double ans = 0;

	for(double i = a;i <= b;i+=1e-7){
		double tmp = -f(i);
		if(tmp >= 0){
			ans += tmp * (1e-7);
		}
	}

	printf("%.12lf\n", ans);

	return 0;
}