(defvar N)
(defvar A)
(defvar temp)
(setq N (parse-integer (read-line)))
(setq A (read-from-string (concatenate 'string "(" (read-line) ")")))


(defvar ari)
(defvar nasi)
(setq ari '())
(setq nasi '())
(loop for i in A do
 (if (find i ari) 
	(progn
	  (setq nasi (append nasi (list i)))
  	  (setq ari (remove i ari))
	)
	(setq ari ( append ari (list i)))
 )
 )
;(print ari)
;(print nasi)
(format t "~d~%" (length ari))