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

Ex Input:
Which 20th century British prime minister had the longest surname ?

Ex Output:
prime minister of the united kingdom


Ex Input:
What is the smallest country in Central America Costa Rica, Venezuela or El Salvador?

Ex Output:
central america


Ex Input:
Dean Martin starred in 4 films as which fictional US government counter-agent, created by Donald Hamilton?

Ex Output:

dean martin