# frozen_string_literal: true
# This file is expanded by nanacl.

main = -> do # =================================================================
# frozen_string_literal: true
# require "nanacl/bsearch_right" # (expanded: L29)
in_r, in_p, in_q = gets.chomp.split.map(&:to_i)
in_a, in_b, in_c, in_d = gets.chomp.split.map(&:to_i)

ans =
  (0..(10**10)).bsearch_right do |n|
    change_budget = in_r - in_p * n
    next false if change_budget < 0
    missing_a = n - in_a
    missing_b = n - in_b
    missing_c = n - in_c

    unuseds = [-missing_a, -missing_b, -missing_c, in_d].sum { |c| [c, 0].max }
    missings = [missing_a, missing_b, missing_c].sum { |c| [c, 0].max }

    missings <= change_budget / in_q && unuseds >= missings
  end

puts ans

end # --------------------------------------------------------------------------

# === dependencies -------------------------------------------------------------
# == nanacl/bsearch_right from main --------------------------------------------
# frozen_string_literal: true

class Array
  def bsearch_right(&)
    index = bsearch_index_right(&)
    index && self[index]
  end

  def bsearch_index_right(&block)
    right = bsearch_index { |elem| !block.call(elem) }
    if right.nil?
      size - 1
    elsif right == 0
      nil
    else
      right - 1
    end
  end
end

class Range
  def bsearch_right(&block)
    right = bsearch { |elem| !block.call(elem) }
    if right.nil?
      last
    elsif right == first
      nil
    else
      right - 1
    end
  end
end


# ==============================================================================

main.call