(DEFUN ONLEVEL(L S)
(COND ((null S) 0)
((AND (> L '0) (ATOM (CAR S))) (ONLEVEL L (CDR S)))
((> L '0) (+ (ONLEVEL (- L 1) (CAR S)) (ONLEVEL L (CDR S))))
(1 (COUNT_S S))
)
)
(DEFUN COUNT_S(S)
(COND ((null S) 0)
((ATOM (CAR S)) (COUNT_S (CDR S)))
(1 (+ 1 (COUNT_S (CDR S))))
)
)
(PRINT (ONLEVEL '2 '(1 (2 (4 (5 6))) 3 5 (6) (7 (8 (10) (11))))))
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