Hello I need help understanding BLP system

Consider a BLP system with the following clearances (classifications) and category sets:

-3 clearances/classification: U S TS

-3 category sets: {ASIA, EUR, US}, {EUR, US}, {US}

(do not consider other unlisted category sets, like {ASIA} or {EUR}. They won't appear in the system)

Question: List all the security levels in the system. (Note: A security level is a pair: (clearance, category set))