(defun play-game (max-players last-marble)
  (let ((scores (make-hash-table))
        (marbles '#1=(0 . #1#)))
    (dotimes (marble (1+ last-marble))
      (if (zerop (rem (1+ marble) 23))
          (let ((end (* 2 (floor marble 23))))
            (setf marbles (nthcdr (- marble end 6) marbles)
                  (cdr (nthcdr (- marble end) marbles)) (cdr marbles))
            (incf (gethash (rem marble max-players) scores 0)
                  (+ 1 marble (pop marbles))))
          (setf (cddr marbles) (cons (1+ marble) (cddr marbles))
                marbles (funcall (if (= 0 marble) 'cdr 'cddr) marbles))))
    (reduce 'max (cons 0 (vals scores)))))