(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((ha (cons #\A (read)))
         (hb (cons #\B (read)))
         (hc (cons #\C (read)))
         (xs (sort (list ha hb hc) #'> :key #'cdr)))
    (loop for x in xs
          do (princ (car x))
             (terpri))))
(main)