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

Ex Input:
What style of facial hair was famously worn by American Civil War general Ambrose Burnside?

Ex Output:
ambrose burnside


Ex Input:
In 2011, Christian Bale won a Best Supporting Actor Oscar for his role as an assistant to his half-brother in which boxing related film?

Ex Output:
christian bale


Ex Input:
Who wrote 'Confessions of an English Opium Eater'?

Ex Output:

confessions of an english opium-eater