Yeah, that disclaimer scared me off at first. I solved D last, but in the end I do feel that it's easier than C. I suppose you can solve C-small with a more naive method though.
The odd thing is, though, I still don't really see how you can solve C-small without solving C-large at the same time (other than actual brute-force). Guess I'll be keeping my eyes peeled for the write-up.