#include <algorithm>
#include <array>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
using namespace std;
typedef long long ll;
#define REP(i,n) for(int i = 0; i < (int)(n); ++i)
#define FOR(i,a,b) for(int i = (a); i < (int)(b); ++i)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(v) ((int)v.size())
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b; return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b; return true;
    }
    return false;
}
#define pb push_back
#define mp make_pair
#define mt make_tuple

int main(void)
{
    cin.sync_with_stdio(false);
    int a, b;
    cin >> a >> b;

    int mx = 1e7;
    double step = (double)(b - a) / mx;
    double ans = 0.0;
    REP(i, mx) {
        double x = a + step * i;
        double y = (x - a) * (x - b);
        // cout << "x, y = " << x << "," << y << endl;
        ans += y * step;
    }
    cout << fixed << setprecision(20) << abs(ans) << endl;

    return 0;
}