#include <bits/stdc++.h>

#define ll long long

using namespace std;

int main() {
	double gf = 1.0;

	double Tf, Vf, Hf, Td, Vd, Hd;
	double sol = 0;
	
	cin >> Tf >> Vf >> Hf >> Td >> Vd >> Hd;
	
	double th = sqrt( 2*(Hf - Hd) );
	double sf = th * Vf;
	double sd = (th - Td) * Vd;
	
	if( sd > sf){
		//cout << "1\n";
		sol = Tf + th + sf/Vd;
	}else{
		double tp = sqrt( 2 * Hf );
		double ts = -Td*Vd/( Vf - Vd );
		
		if(th < ts && ts < tp){
			//cout << "3\n";
			double hs = Hf - ts*ts/2;
			sol = Tf + ts + Vf * ts / Vd + sqrt(2*hs/3);
		}else{
			//cout << "2\n";
			double sff = tp * Vf;
			sol = Tf + (Td - Tf) + sff/Vd + sff/Vd;
		}
	}
	
	printf("%.10lf\n", sol);

	return 0;
}