(defun main (&rest argv)
  (declare (ignorable argv))
  (let* ((n (read))
         (m (read))
         (xs (make-array (1+ n) :element-type 'integer :initial-element m))
         (ys (make-array (1+ n) :element-type 'integer :initial-element 0)))
    (loop for i from 1 to m
          do (loop for j to n by i
                   do (setf (aref xs j) (- (aref xs j) i))))
    (loop for i below n
          do (setf (aref ys (1+ i)) (+ (aref ys i) (aref xs (1+ i)))))
    (princ (reduce #'max ys))
    (terpri)))

(main)