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

Example Input: In the British Army, what rank falls between Major General and Colonel?
Example Output: british army

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: What was the name of the horse on which jockey Richard Dunwoody won the 1986 Grand National?
Example Output:
1986 grand national