def frequent_words(text)
  text.downcase!
  words = text.scan(/[[:alpha:]']+/)
  frequency = words.tally

  if frequency.length >= 3
    sorted = frequency.sort_by { |key, value| -value }
    sorted.each_with_index do |element, index|
      puts "#{index + 1} most frequent word is: #{element}" if index < 3
    end
  else
    words.clear
    puts "Not enough words!\n#{words}"
  end
end

frequent_words "hi, there, D'ark brave silly d'Ark, HI, hI) brAvE, d'ARK -hi"