h, w, la, lb, ka, kb = map(int, input().split())

ans = 1 << 60
if ka != 0:
  ans = min(ans, (h * w + ka - 1) // ka)
if kb != 0:
  ans = min(ans, (h * w + kb - 1) // kb)

b = 0
for a in range(h, -1, -1):
  while b < w:
    cnt = min(h, a * la) * min(w, b * lb) + a * ka + b * kb
    if cnt >= h * w:
      break
    b += 1
  cnt = min(h, a * la) * min(w, b * lb) + a * ka + b * kb
  if cnt >= h * w:
    ans = min(ans, a + b)

print(ans)