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

Input: Consider Input: Which group had UK top ten hits in 1987 with 'Sweet Little Mystery' and 'Angel Eyes'?

Output: angel eyes

Input: Consider Input: Of all the actors who played Doctor Who in the TV series of the same name, who appeared in the most episodes?

Output: doctor who

Input: Consider Input: Which branch of science has four fundamental principles: addition, subtraction, multiplication, and division.?
Output: division