r, p, q = read_line.split.map(&.to_i64)
a, b, c, d = read_line.split.map(&.to_i64)
cs = [a, b, c]
lo = 0i64
hi = cs.sum + d
while hi - lo > 1
  mid = (lo + hi) // 2
  u = cs.sum { |v| {mid - v, 0i64}.max }
  if u > d
    hi = mid
    next
  end
  if u * q + mid * p > r
    hi = mid
  else
    lo = mid
  end
end
puts lo