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

using ll = long long int;
using ull = unsigned long long int;
using P = pair<int, int>;
using P3 = pair<double,P>;
using PP = pair<P, P>;
constexpr int INF = 1 << 30;
constexpr ll MOD = ll(1e9)+7;
constexpr int di[] = {0, 1, 0, -1};
constexpr int dj[] = {1, 0, -1, 0};
constexpr double EPS = 1e-9;

double a, b;
double f(double x){
    return (x-a)*(x-b);
}

int main(){
    cin >> a >> b;
    int n = 100000;
    double ans = 0, dx = (b-a)/double(n);
    for(int i=0;i<n;i++){
        double x = a+dx*i;
        ans += abs(f(x))*dx;
    }
    printf("%.6lf\n",ans);
    return 0;
}