#lang racket
(define a (list 1 3 (list 5 7) 9))
(car (cdr (car (cdr (cdr a)))))

(define b (list (list 7)))
(car (car b))

(define c (list 1 (list 2 (list 3 (list 4 (list 5 (list 6 (list 7))))))))
(car (car (cdr (car (cdr (car (cdr (car (cdr (car (cdr (car (cdr c)))))))))))))