module Week
  FIRST_DAY = "Sunday"
  def Week.weeks_in_month
    puts "You have four weeks in a month"
  end
  def Week.weeks_in_year
    puts "You have 52 weeks in a year"
  end
end


class Decade
  include Week
  no_of_yrs=10
  def no_of_months
    puts Week::FIRST_DAY
    number=10*12
    puts number
  end
end
d1=Decade.new
puts Week::FIRST_DAY
Week.weeks_in_month
Week.weeks_in_year
d1.no_of_months