If a working fault tolerant quantum computer landed on your desk tomorrow, what would you run first

[Delulu66]

Assume it's genuinely capable, no caveats about noise or limited qubit count. Would you point it at something practical like a materials simulation, try to break a small cryptographic puzzle just to watch it happen, or just poke at something purely for curiosity's sake. Interested in the actual first instinct rather than the sensible answer.