(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 main ()
  (let ((a (read))
        (b (read)))
    (println (- (logior a b)
                (logand a b)))))

#-swank (main)