(defun read-fish (name)
  (flow
    (file-get-string name)
    (tok #/\d+/)
    (mapcar toint)))

(defun sim-naive (input n)
  (while (plusp (pdec n))
    (upd input (mappend [iff zerop (ret '(6 8)) [chain pred list]])))
  (len input))

(defun sim (input n)
  (let ((phase (vector 9 0)))
    (each ((i input))
      (inc [phase i]))
    (while (plusp (pdec n))
      (rotate [phase 0] [phase 1] [phase 2]
              [phase 3] [phase 4] [phase 5]
              [phase 6] [phase 7] [phase 8])
      (inc [phase 6] [phase 8]))
    (sum phase)))

(defun sim2 (input n)
  (let ((phase (vector 9 0)))
    (each ((i input))
      (inc [phase i]))
    (while (plusp (pdec n))
      (pset [phase 8] [phase 0]
            [phase 0..8] [phase 1..9])
      (inc [phase 6] [phase 8]))
    (sum phase)))