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

[EX Q]: Who played Captain Jean-Luc Picard in the television series 'Star-Trek: The Next Generation'?
[EX A]: jean-luc picard

[EX Q]: What was the first Apollo mission to leave Earth orbit and orbit the moon, in 1968?
[EX A]: apollo

[EX Q]: Which of these is the real name of an Airport based in Calcutta?
[EX A]:
kolkata