#include <bits/stdc++.h>
using namespace std;
int main(){
  cout << fixed << setprecision(20);
  double a, b, c, d, e, f;
  cin >> a >> b >> c >> d >> e >> f;
  cout << sqrt(c * c / a / 4 + d * d / b / 4 - e + f) << endl;
}