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

Ex Input:
Physics. What is the SI unit for amount of substance?

Ex Output:
amount of substance


Ex Input:
Which BBC current affairs programme, the longest-running in the world, is 60 years old this year ?

Ex Output:
bbc


Ex Input:
Which actor took the lead roles in the films, 'Blade Runner', 'The Hitcher', and 'Flesh And Blood'?

Ex Output:

flesh and blood