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

Example Input: In which Indian city is Eden Gardens, the second largest test cricket ground in the world?
Example Output: eden gardens

Example Input: The headquarters building of which government agency is known as 'The Doughnut' due to its shape?
Example Output: the doughnut

Example Input: What actress starred in Avatar and Aliens?
Example Output:
aliens