#include "stdio.h"
#include "stdlib.h"
#include <bits/stdc++.h>


using namespace std;
int main() {
	double tf, vf, hf, td, vd, hd;
	cin >> tf >> vf >> hf >> td >> vd >> hd;
	double t_fall = sqrt(2 * hf);
	double s_fall = t_fall * vf;
	
	if (vd <= vf) {
		printf("%f\n", td + (s_fall / vd) * 2);
		return 0;
	}
	
	double  sf = vf * (td - tf);
	double  t = sf / (vd - vf);
	if ((t + td - tf) >= t_fall) {
		printf("%f\n", td + (s_fall / vd) * 2);
		return 0;
	}
	double h = hf - 1/2 * (td - tf + t) * (td - tf + t);
	if (h <= hd) {
		printf("%f\n", td + t*2);
		return 0;
	}
	double t2 = sqrt(2 * (hf - hd));
	double s2 = vf * t2;
	printf("%f\n", tf + t2 + s2/vd);
	return 0;
}