1 (defun divides? (a b)
2   (= (rem b a) 0))
3 (defun my-cons (a b)
4   (* (expt 2 a) (expt 3 b)))
5 (defun my-car (z)
6   (do ( (n 0 (1+ n))
7 	(aa z (/ aa 2)))
8       ((not (divides? 2 aa)) n)))
9 (defun my-cdr (z)
10   (do ( (n 0 (1+ n))
11 	(aa z (/ aa 3)))
12       ((not (divides? 3 aa)) n)))