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

Example Input: To which country do the Chatham Islands belong?
Example Output: chatham islands

Example Input: The counties of Alameda, El Dorado, Fresno, Marin, Mariposa, Nevada, Orange, Riverside, Sacramento, San Bernardino, San Joaquin, San Mateo, Santa Clara, Santa Cruz, Sonoma and Ventura are in what state of the USA?
Example Output: santa clara, california

Example Input: At which narrow pass did Leonidas and 300 Spartans fight to the death, in order to slow down the Persian army?
Example Output:
battle of thermopylae