#include<cstdio>
#include<math.h>

const double eps = 0.000001;

int main(){
	double tf, td, vf, vd, hf, hd, t;
	scanf("%lf%lf%lf%lf%lf%lf", &tf, &vf, &hf, &td, &vd, &hd);

	//td = td - tf; //here td, tf from beggining
	
	// CASE FALLS BEFORE Td
	if(td * td > 2 * hf + eps){
		t = sqrt(2*hf);
		printf("%f", td + 2 * vf * t / vd);
		return 0;
	}
	
	t = (vf * (td - tf)) / (vf - vd); 
	
	// CASE FALLS AFTER Td, BEFORE DOG REACHES
	if(2*hf - t*t < eps || vd < vf){
		t = sqrt(2*hf);
		printf("%f", td + 2 * vf * t / vd);
		return 0;
	}
	
	// CASE REACHES BENEATH Hd
	if(2*hf - t*t - hd < eps){
		printf("%f", td + 2*t);
		return 0;
	}
	
	// CASE REACHES ABOVE Hd
	t = sqrt(2*(hf - hd));
	double sp = t*vf;
	printf("%f", tf + t + sp/vd);
	return 0;
}