#ifndef LOCAL
#pragma GCC optimize("O3")
#endif
#include <bits/stdc++.h>
using namespace std;
#define sim template <class c
#define mor > muu & operator<<(
#define ris return *this
#define eni(r) sim> typename enable_if <1 r sizeof(dud<c>(0)),muu&>::type operator<<(c g) {
sim> struct rge {c b,e ;};
sim> rge<c> range(c i, c j) {return rge<c>{i, j};}
sim> auto dud(c *r)-> decltype(cerr << *r);
sim> char dud(...);
struct muu {
	#ifdef LOCAL
	stringstream a;
	~muu() {cerr << a.str() << endl;}
	eni(<) a << boolalpha << g; ris;}
	eni(==) ris << range(begin(g), end(g));}
	sim, class m mor pair<m,c> r) {ris << "(" << r.first << ", " << r.second << ")";}
	sim mor rge<c> u) {
		a << "[";
		for (c i = u.b; i != u.e; ++i)
			*this << ", " + 2 * (i == u.b) << *i;
		ris << "]";
	}
	#else
	sim mor const c&) {ris;}
	#endif
	muu & operator()(){ris;}
};
#define debug (muu() << __FUNCTION__ << "#" << __LINE__ << ": ")
#define imie(r) "[" #r ": " << (r) << "] "
#define imask(r) "[" #r ": " << bitset<8 * sizeof(r)>(r) << "] "
#define arr(a, i) "[" #a imie(i) ": " << a[i] << "] "
#define arr2(a, i, j) "[" #a imie(i) imie(j) ": " << a[i][j] << "] "

using ld = long double;
ld eps = 1e-10;

ld tf, vf, hf, td, vd, hd;
ld res;

ld tz;

void naZiemi() {
	ld top = sqrt(2. * hf);
	ld tbg = td + vf * top / vd;
	res = max(top, tbg) + vf * top / vd;
	debug << "na ziemi " << res;
}

bool check(ld y) {
	ld t = sqrt(2. * (hf - y));
	if (t < tz) return false;
	ld v0 = sqrt(6.0 * hd);
	ld tp = (v0 - sqrt(v0 * v0 - 6. * y)) / 3.;
	return td + tp <= t;
}

ld czas(ld y) {
	ld t = sqrt(2. * (hf - y));
	ld x = vf * t;
	return t + x / vd;
}

int main() {
	cin >> tf >> vf >> hf >> td >> vd >> hd;
	td -= tf;
	naZiemi();
	
	if (vd > vf + 1e-5) {
		tz = vd * td / (vd - vf);
		
		ld p = 0;
		ld k = hd - eps;
		
		for (int it = 0; it < 60 && p < k; ++it) {
			ld s = (p + k) / 2.;
			if (check(s)) {
				res = min(res, czas(s));
				p = s;
			}
			else k = s;
		} 
	}
	
	cout.precision(10);
	cout << fixed;
	cout << res + tf << endl;
	return 0;
}