@amszmidt @screwtape Hah, this reminds me of this craziness from my early days:
First is first, last is a list of last.
When given the list ((10 (20 30 40) 50) 60 70)), output the first of the last of the first of the last of the first element, and name the accessor.
(The answer is 30, and CADADAR, but of course you all already knew that right away)