(defun count-unique-concatenations (string-list)
  (let ((result '()))
    (loop for i from 0 below (length string-list) do
      (loop for j from 0 below (length string-list) do
        (when (not (= i j))
          (let ((combined (concatenate 'string (nth i string-list) (nth j string-list))))
            (pushnew combined result :test 'equal)))))
    (length result)))

(defun main ()
  (let ((n (read)))
    (let ((string-list (loop for i from 0 below n collect (read-line))))
      (format t "~d~%" (count-unique-concatenations string-list)))))

(main)