import sys
import math

def s(t, v, a):
	return v * t + 1/2 * a * t * t

inp = sys.stdin.readline()

tf, vf, hf, td, vd, hd = map(int, inp.split())

t_fall = math.sqrt(2 * hf)
s_fall = t_fall * vf

if vd <= vf:
	print(td + (s_fall / vd) * 2)
else:
	sf = (td - tf) * vf
	t = sf/(vd - vf)
	if t_fall < t + td - tf:
		#print('fall before dog reaches')
		print((s_fall / vd) * 2 + td)
	else:
		h = hf - 1/2*((t + td - tf) ** 2)
		if h <= hd:
			#print('norm hugh for dog')
			print(td + 2*t)
		else:
			t2 = math.sqrt((hf - hd) * 2)
			sf = t2 * vf
			#print('wait frisbee to be lower', sf)
			print(tf + t2 + sf/vd)
exit(0)