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

Who plays Dr Evil the nemesis of Austin Powers in the Austin Powers series of films?
austin powers

What is the name of the main thoroughfare in Barcelona, which runs from the Placa de Catalunya to the sea?
barcelona

In ancient history, which Carthagian general beat the Romans at Cannae in 216 BC?
battle of cannae