(define (queHace lista)
    (cond
          ((null? lista) lista)
      ((list? (car lista)) (append (queHace (cdr lista)) (list (queHace (car lista)))))
      (else (append (queHace (cdr lista)) (list (car lista))))))

(queHace '(3 4 (5 6) 9))
(append (queHace '(4 (5 6) 9)) (list 3))
(append (append (queHace '((5 6) 9)) (list 4)) '(3))
(append (append (append (queHace '(9)) (list (queHace '(5 6)))) '(4)) '(3))
(append (append (append (append (queHace '()) (list (9))) (list (append (queHace '(6)) (list 5)))) '(4)) '(3))
(append (append (append (append '() '(9)) (list (append (append (queHace '()) (list 6)) '(5)))) '(4)) '(3))
(append (append (append '(9) (list (append (append '() '(6)) '(5)))) '(4)) '(3))
(append (append (append '(9) (list (append '(6) '(5)))) '(4)) '(3))
(append (append (append '(9) (list '(6 5))) '(4)) '(3))
(append (append (append '(9) '((6 5))) '(4)) '(3))
(append (append '(9 (6 5)) '(4)) '(3))
(append '(9 (6 5) 4) '(3))
'(9 (6 5) 4 3)