#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ul = unsigned long;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

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

    double res = sqrt((f - e + ((c * c + d * d) / 4.0 / a)) / a);
    cout << fixed << setprecision(15) << res << "\n";

    return 0;
}