words.cr

h = {} of UInt64 => Array(String)
STDIN.each_line do |line|
  line = line.chomp
  hv = line.hash
  if h.has_key?(hv)
    ar = h[hv]
    unless ar.includes?(line)
      ar.push(line)
    end
  else
    h[hv] = [line]
  end
end

h.each do |hv, ar|
  if ar.size > 1
    puts hv
    p ar
  end
end