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

typedef long long int LL;
typedef double LD;

const int MAXN = 1000*1000;
const LD EPS = 1e-6;

LD Tf, Vf, Hf, Td, Vd, Hd;
LD delta;

bool Check(LD t){
	LD s1 = (t+delta)*(t+delta)/2.0;
	LD s2 = min(Hd, 1.5*t*t);
	return s1+s2 >= Hf;
}

int main(){
	scanf("%lf %lf %lf %lf %lf %lf", &Tf, &Vf, &Hf, &Td, &Vd, &Hd);
	delta = Td - Tf;
	if(Vf + EPS > Vd){//sprawdzone
		LD Tfall = sqrt(2.0*Hf);
		printf("%.9lf\n", 2.0*Tfall*Vf/Vd + Td);
		return 0;
	}
	LD T = delta*Vf/(Vd-Vf);
	LD Tfall = sqrt(2.0*Hf);
	if(Tfall - delta <= T){
		printf("%.9lf\n", 2.0*Tfall*Vf/Vd + Td);
		//printf("chuj");
		return 0;
	}
	
	LD A = T, B = Tfall-delta, t = 0.0;
	
	//printf("%lf %lf\n", A, B);
	
	for(int i=0; i<100000; i++){
		t = (A+B)/2.0;
		if(Check(t))
			B = t;
		else
			A = t;
	}
	
	t = (A+B)/2.0;
	
	//printf("%.9lf\n", t);
	
	//printf("%.9lf\n", 2.0*(delta+t)*Vf/Vd + Td);
	printf("%.9lf\n", Td + t + (delta+t)*Vf/Vd);
	//printf("%.9lf\n", Td + t + (t)*Vf/Vd);
	
	return 0;
	
}