(defun f (b n dp scores)
  (if (/= -1 (aref dp b))
      (aref dp b)
      (let ((m 0))
        (dotimes (i n)
          (unless (zerop (logand 1 (ash b (- i))))
                  (let ((s (f (logxor b (ash 1 i)) n dp scores)))
                    (dotimes (j n)
                      (incf s (* (logand 1 (ash b (- j))) (aref scores (+ j (* i n))))))
                    (setf m (max m s)))))
        (setf (aref dp b) m)
        m)))

(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((n (read))
         (m (read))
         (scores (make-array (* n n)))
         (dp (make-array (ash 1 n) :element-type 'integer :initial-element -1))
         (res 0))
    (dotimes (i m)
      (let* ((item1 (read))
             (item2 (read))
             (score (read)))
        (setf (aref scores (+ (* item1 n) item2)) score)))
    (setf (aref dp 0) 0)
    (setq res (f (1- (ash 1 n)) n dp scores))
    (format t "~d~%" res)))

(main)