Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Ex Input:
In which Shakespeare play do the characters Ajax, Achilles and Ulysses appear?

Ex Output:
achilles

Ex Input:
Which exponent of Brit Art created works involving a bed, a tent and a beach hut?

Ex Output:
young british artists

Ex Input:
Who was the next British Prime Minister after Arthur Balfour?

Ex Output:
prime minister of the united kingdom