(declaim (inline println))
(defun println (obj &optional (stream *standard-output*))
  (let ((*read-default-float-format* 'double-float))
    (prog1 obj
      (princ obj stream)
      (terpri stream))))

(defun ok (xs)
  (sb-int:named-let rec ((xs xs)
                         (c #\a))
    (or (null xs)
        (and (char<= c (first xs))
             (rec (rest xs)
                  (first xs))))))

(defun get-l-and-r (xs)
  (when (ok xs)
    (list (length xs)
          (first (sort (copy-seq xs) #'char<))
          (first (sort (copy-seq xs) #'char>)))))

(define-modify-macro maxf (var) max)

(defun char->int (c)
  (- (char-code c)
     (char-code #\a)))

(defun main ()
  (let* ((n (read))
         (ss (sort (remove-if #'null (mapcar #'get-l-and-r (loop repeat n collect (concatenate 'list (read-line))))) #'char< :key #'second)))
    (let ((dp (make-array 26 :initial-element 0)))
      (loop for (cnt l r) in ss
            do (maxf (aref dp (char->int r))
                     (+ (aref dp (char->int l))
                        cnt)))
      (println (reduce #'max dp)))))

#-swank (main)