#include <bits/stdc++.h>
using namespace std;

#define TRACE(x) cerr << #x << ' ' << x << endl
#define FOR(i, a, b) for (int i = (a); i < int(b); i++)
#define REP(i, n) FOR(i, 0, n)
#define _ << ' ' <<

typedef long long llint;
typedef long long ll;
typedef pair <int, int> pii;

#define fi first
#define sec second
#define pb push_back

double Tf, Vf, Hf, Td, Vd, Hd;

bool check(double T) {
  double H = Hf - T * T / 2;
  if (Hd < H) return false;

  double Tjump = (sqrt(Hd * 6) - sqrt((Hd - H) * 6)) / 3;
  double Trun = T - (Td - Tf);

  return Tjump <= Trun && Trun * Vd >= T * Vf;
}

int main() {
  cin >> Tf >> Vf >> Hf >> Td >> Vd >> Hd;
  double sol;
  
  double maxT = sqrt(Hf * 2);

  if (!check(maxT)) {
    sol = Vf * maxT / Vd * 2 + Td;
  } else {
    double lo = 0, hi = maxT;

    for (int iter = 0; iter < 1000; iter++) {
      double mid = (lo + hi) / 2;
      if (check(mid)) hi = mid;
      else lo = mid;
    }

    sol = Tf + lo + Vf * lo / Vd;
  }

  cout << fixed << setprecision(7) << sol;

  return 0;
}