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

#define PII pair<int, int>
#define VI vector<int>
#define VPII vector<PII>
#define LL long long
#define f first
#define s second
#define MP make_pair
#define PB push_back
#define LD long double
#define endl '\n'
#define ALL(c) (c).begin(), (c).end()
#define SIZ(c) (int)(c).size()
#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, b, e) for (int i = (b); i <= (int)(e); i++)
#define FORD(i, b, e) for (int i = (b); i >= (int)(e); i--)
#define ll LL
#define mp MP
#define pb PB
#define st f
#define nd s
#define eb emplace_back
const int inf = 1e9 + 7;
const LL INF = 1e18L + 7;

#define sim template<class n
sim, class s> ostream & operator << (ostream &p, pair<n, s> x)
{return p << "<" << x.f << ", " << x.s << ">";}
sim> auto operator << (ostream &p, n y) ->
typename enable_if<!is_same<n, string>::value, decltype(y.begin(), p)>::type
{int o = 0; for (auto c : y) {if (o++) p << ", "; p << c;} return p << "}";}
void dor() {cerr << endl;}
sim, class...s> void dor(n p, s...y) {cerr << p << " "; dor(y...);}
sim, class s> void mini(n &p, s y) {if (p > y) p = y;}
sim, class s> void maxi(n &p, s y) {if (p < y) p = y;}

#ifdef DEB
#define debug(...) dor(__FUNCTION__, ":", __LINE__, ": ", __VA_ARGS__)
#else
#define debug(...)
#endif

#define I(x) #x " =", (x), " "
#define A(a, i) #a "[" #i " =", i, "] =", a[i], " "
const int M = 1024 * 1024;

LD tf, vf, hf, td, vd, hd, vp;

bool check(LD t, LD h, LD dd)
{
	LD delta = vp * vp - 6 * h;
	if (vd * t < dd)
	{
		return false;
	}
	if (delta < 0)
	{
		return false;
	}
	LD tt;
	if (vp >= sqrt(delta))
	{
		tt = (vp - sqrt(delta)) / 3;
	}
	else
	{
		tt = (vp + sqrt(delta)) / 3;
	}
	return tt <= t;
}

int main()
{
	scanf("%Lf%Lf%Lf%Lf%Lf%Lf", &tf, &vf, &hf, &td, &vd, &hd);
	td -= tf;
	
	vp = sqrt(6 * hd);
	LD st = 0, en = vf * sqrt(2 * hf), res = max(en / vf, en / vd + td) + en / vd, mid = (st + en) / 2;
	//printf("%Lf\n", res);
	FOR(i, 1, 100)
	{
		LD t = mid / vf;
		LD h = hf - t * t / 2;
		if (check(t - td, h, mid))
		{
			res = min(res, t + mid / vd);
			en = mid;
		}
		else
		{
			st = mid;
		}
		mid = (st + en) / 2;
	}
	printf("%.9Lf\n", res + tf);
}