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

Example Input: Which `brothers` had a number one hit in May 1958 with `All I Have To Do Is Dream`?
Example Output: all i have to do is dream

Example Input: In 1864, the Dale Dyke Dam burst while being filled, leading to the death of 240 people in which British city?
Example Output: dale dike reservoir

Example Input: Colby O'Donis featured on which Lady Gaga hit?
Example Output:
lady gaga