#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <set>
#include <iostream>
#include <cassert>
#include <cstring>
#include <iomanip>

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define REP(i,n) FOR(i,0,n)

#define TRACE(x) cerr << #x << " = " << x << endl
#define _ << " _ " <<

#define pb push_back
#define X first
#define Y second

using namespace std;

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

const double eps = 1e-9;
inline bool lt(double a, double b) { return a + eps < b; }
inline bool gt(double a, double b) { return lt(b, a); }
inline bool eq(double a, double b) {return !lt(a, b) && !gt(a, b); }
inline bool lte(double a, double b) { return !gt(a, b);}

inline double sqr(double x) { return x*x;}

double T_f, V_f, H_f, T_d, V_d, H_d;
double t_term,v_up, t_up;
double res = 0;

double d_dog(double t) {
  return V_d * (t - T_d);
}

double d_friz(double t) {
  if (lte(t, t_term))
    return V_f * t;
  else
    return V_f * t_term;
}

double h_dog(double t) {
  if (lte(t, T_d)) return 0.;
  else if (lte(t - T_d, t_up))
    return v_up * (t - T_d) - 3. * sqr(t - T_d) / 2; //maybe just first arg
  else return H_d;
}

double h_friz(double t) {
  return max(H_f - sqr(t) / 2., 0.);
}

bool ok(double t) {
  return lte(h_friz(t), h_dog(t)) && lte(d_friz(t), d_dog(t));
}

void solve() {
  double lo = 0, hi = 1e18;

  REP(i, 5000) {
    double t = (lo + hi) / 2;
    if (ok(t)) hi = t;
    else lo = t;
  }

  //  TRACE(lo _ h_friz(lo) _ h_dog(lo) _ d_dog(lo) _ d_friz(lo));
  res += lo;
  double t = lo;

  res += d_friz(t) / V_d;

  cout << fixed << setprecision(9) << res << endl;
}

void load() {
  cin>>T_f>>V_f>>H_f>>T_d>>V_d>>H_d;

  res += T_f;
  T_d -= T_f;
  T_f = 0;

  t_term = sqrt(2. * H_f);
  v_up = sqrt(6. * H_d);
  t_up = v_up / 3.;
}


int main(){
  ios_base::sync_with_stdio(false);
  load();
  solve();
  
  return 0;
}

/* lo _ h_friz(lo) _ h_dog(lo) _ d_dog(lo) _ d_friz(lo) = 15.4919 _ 40 _ 40 _ 38.9516 _ 30.9839
22.983866770
*/