class Calc0106
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @n, @k = args.shift.map(&:to_i)
  end

  def run
    return @n - 1 if @k == 1

    @memo = Array.new(@n + 1) { 0 }
    (2..(@n / 2)).each do |m|
      if @memo[m] == 0
        m.step(@n, m) do |i|
          @memo[i] += 1
        end
      end
    end
    @memo.select { |v| v >= @k }.size
  end
end

puts Calc0106.new(STDIN.readlines).run if __FILE__ == $0