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

Ex Input:
In Curse of the Pink Panther who plays Clouseau after surgery?

Ex Output:
curse of the pink panther


Ex Input:
Who plays Isobel Crawley in the UK television series 'Downton Abbey'?

Ex Output:
downton abbey


Ex Input:
Up to 2016, which of these songs, reaching number 4 on the UK Charts, was the highest charting single by ACDC?

Ex Output:

ac/dc