; MIT License
; Copyright (C) 2022 Shintaro Mukai.
; https://mukai.systems/articles/7g8qtipoaa2083lfave1mol8c0kahlir/

; uniq.

(function! main (args)
  (let (line nil pre (read-line))
    (while (<- line (read-line))
      (when (!= line pre)
        (write-line pre)
        (<- pre line)))
    (write-line pre)))