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

Ex Input:
Who played the title role in the 1955 film 'Davy Crockett, King Of The Wild Frontier'?

Ex Output:
davy crockett


Ex Input:
Which horse won the 2008 Grand National?

Ex Output:
2008 grand national


Ex Input:
What is the name for the branch of astronomy that relates to precise measurements and explanations of the positions and movements of celestial bodies?

Ex Output:

astronomy