#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <functional>
#include <numeric>
#include <set>
#include <cmath>
// #include <bits/stdc++.h>


using namespace std;
typedef long long li;

typedef double real;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    real a, b, c, d, e, f;
    cin >> a >> b >> c >> d >> e >> f;

    real x = 0, y = 0;
    real eps = 1e-4;

    // f(x, y) = ax^2 + by^2 + cx + dy + e - f
    for (int itr = 0; itr < 100000; ++itr) {
        real grad_x = 2 * a * x + c;
        real grad_y = 2 * b * y + d;
        x -= eps * grad_x;
        y -= eps * grad_y;

//        eps *= 0.999;
    }

    real neg_sq = a * x * x + b * y * y + c * x + d * y + e - f;
    cout.precision(12);
    cout << sqrt(-neg_sq) << endl;

    return 0;
}