
data = Array.new(4)
i = 0

#p data
=begin

File.open("test/0277","r") do |input|
	while data[i] = input.gets do
 		#p data[i]
 		i += 1
	end
end
=end


	while data[i] = input.gets do
 		#p data[i]
 		i += 1
	end

	
for i in data
	if i == nil 
		break
	end
	a,b = (i.chomp).split(" ").map(&:to_i)

	case a 
	when 1 
		a = 6000
	when 2
		a = 4000
	when 3
		a = 3000
	when 4
		a = 2000
	end
	p a*b
end