;(mod (num)
;    (defun count-even (numbers)
;        (if numbers
;            (+ (not (r (divmod (f numbers) 2)))
;                (count-even (r numbers)))
;            0)
;    )
;    (count-even num)
;)

(a (q 2 2 (c 2 (c 5 (q)))) (c (q 2 (i 5 (q 16 (not (r (divmod 9 (q . 2)))) (a 2 (c 2 (c 13 (q))))) (q 1)) 1) 1))