n = gets.to_i
cheby = gets.strip.split(' ').map(&:to_i)
#p @cheby
goal = gets.strip.split(' ').map(&:to_i).map(&:abs)
#p @goal

if goal == [0, 0]
	puts "0"
	exit
end

goal_max = goal.max
cheby_max = cheby.max

if cheby.include?(goal_max)
	puts "1"
	exit
end

if goal_max < cheby_max
	puts (goal.max.to_f / cheby.max).ceil + 1
else
	puts (goal.max.to_f / cheby.max).ceil
end