h,w,la,lb,ka,kb = map(int,input().split())
ans = h + w
for i in range(h + w + 1):
	x = min(h, la * i)
	suki = h + w
	kirai = -1
	while suki - kirai > 1:
		targ = (suki + kirai) // 2
		y = min(w, lb * targ)
		if h * w - x * y <= ka * i + kb * targ:
			suki = targ
		else:
			kirai = targ
	ans = min(ans, i + suki)
print(ans)