Stone cold into a recursive linguistic tree problem that required multiple classes, discussion, diagramming, and iterative build/inspection approach, but had to do it in a flat web page with none of the usual tools you would use to query, plan, and resolve it. A waste of time off work with a convoluted high school problem unrelated to real-world day-to-day duties. Mostly about making the interviewer feel like the cleverest person in the room, so I bowed out.