pretty_old_woman.rb

history = []

puts 'Hello! May I help you?'

while words = gets.chomp
  history << words

  break if history.last(3) == %w(BYE BYE BYE)

  case words
  when 'BYE'
    # do nothing
  when words.upcase
    puts "Well, it hasn't happened since #{rand(1930..1950)}!"
  else
    puts 'Huh? Could you speak up, please??'
  end
end

puts 'Thanks. Come back anytime.'