Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: Aragon and Castile joined to form which country?

Answer: aragon

Question: Which British Prime Minister signed the 'Entente Cordiale' in 1904?

Answer: prime minister of the united kingdom

Question: Which 'brothers' had a number one hit in May 1958 with 'All I Have To Do Is Dream'?

Answer:
all i have to do is dream