A hint searches one assumption deep, and every round here is built so that this always shows at least one move (a hint never goes silent). So why a second floor? When you skip hints and go for the 🧠 mark, you may want to prove one particular cell yourself, and a single assumption cannot always reach it. Hence the picture: two pins, an assumption inside an assumption — the second floor. Second-floor moves still count toward the 🧠 mark (the judge checks two levels deep in the background). Puzzles of this kind are, in general, proven to be among the hardest problems even for computers. This cliff is for bragging rights — climb it yourself and it stays yours for life.

In the app, one new tip arrives for each day you play.

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