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

typedef long double T;

T solve(T b, T c)
{
	T delta = b * b - 4 * c;
	if(delta < 0) return -1;
	return (-b + sqrt(delta)) / 2;
}

int main()
{
	int Tf, Vf, Hf, Td, Vd, Hd;
	scanf("%d %d %d %d %d %d", &Tf, &Vf, &Hf, &Td, &Vd, &Hd);
	T tg = sqrt(2 * Hf);
	T dist = tg * Vf;
	T ans = 1e30;
	if(dist / Vd + Td >= tg + Tf)
		ans = Td + 2 * dist / Vd;
	if(Vd > Vf)
	{
		T t1 = sqrt(2 * (Hf - Hd)) + Tf;
		//printf("%.10Lf %.10Lf\n", t1, sqrtl(2.0 * Hd / 3) + Td);
		if(t1 < sqrt(2.0 * Hd / 3) + Td)
		{
			T vh = sqrt(2.0 * 3 * Hd) + Td - Tf;
			t1 = solve(-vh, Hf - 0.5 * (T)(Td - Tf) * (Td - Tf));
			//printf("%.10Lf\n", t1);
			if(t1 < 0) t1 = 1e30;
			else t1 += Td;
		}
		T t2 = (T)Vf * (Td - Tf) / (Vd - Vf) + Td;
		//printf("%.10Lf %.10Lf\n", t1, t2);
		if(t1 <= t2)
		{
			ans = min(ans, 2 * t2 - Td);
			//puts("a");
		}
		else
		{
			dist = (t1 - Tf) * Vf;
			//printf("%.10Lf\n", dist);
			ans = min(ans, t1 + dist / Vd);
			//puts("b");
		}
	}
	printf("%.10Lf\n", ans);
}