#include <bits/stdc++.h>

namespace solver{
  void solve(){
    double a, b, c, d, e, f; std::cin >> a >> b >> c >> d >> e >> f;
 
    //assert(a == b and a != 0 and b != 0);

    double ans = std::sqrt(f - e + c * c / (4 * a) + d * d / (4 * b));
    std::cout << std::fixed << std::setprecision(15) << ans << "\n";
  }
}

int main(){
  solver::solve();
  return 0;
}