module Mark_twain
  def mark_twain
    mark_twain_helper(self, [])
  end

  def mark_twain_helper(str, accum_ar)
    if str.split.length == 1
      accum_ar << "Final draft: #{str}."
      accum_ar
    else
      accum_ar << "Draft: #{str}."
      reduced_str = str.split[(0..-2)].join(" ")
      mark_twain_helper( reduced_str , accum_ar )
    end
  end
end

class String
  include Mark_twain
end