class Calc0128
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @n = args.shift.first.to_i
    @m = args.shift.first.to_i
  end

  def run
    @n / 1000 / @m * 1000
  end
end

puts Calc0128.new(STDIN.readlines).run if __FILE__ == $0