(defun char-code-max (a b)
  (if (char>= a b) a b))

(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((n (read))
         (res 9876543219876543210))
    (dotimes (_ n)
      (let* ((v (read-line))
             (base (1+ (parse-integer (string (reduce #'char-code-max v)) :radix 36))))
        (setq res (min res (parse-integer v :radix base)))))
    (format t "~d~%" res)))

(main)