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

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: Who succeeded Jon Pertwee as Doctor Who?
Example Output: doctor who

Example Input: Whose last literary work was the TV play Karaoke and Cold Lazarus?
Example Output:
cold lazarus