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

Ex Input:
Who directed the film Black Swan (in ballet)?

Ex Output:
black swan


Ex Input:
Richard Addinsell's most famous piece of music was used in the 1941 film 'Dangerous Moonlight', what is its title?

Ex Output:
dangerous moonlight


Ex Input:
Black Cat gave who their second No.1 of the 1990s?

Ex Output:

black cat