require 'date'

module HappyDay
  def solve
    (Date.new(2015, 1, 1) .. Date.new(2015, 12, 31)).reduce(0){|ct, d|
      d10, d1 = d.day.divmod(10)
      if d.month == d10 + d1
        ct + 1
      else
        ct
      end
    }
  end
  module_function :solve
end

puts HappyDay.solve