Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
--------
Question: The bells were ringing for Chuck Berry when this song made it to No1. His first and only British No. 1. What song?

Answer: chuck berry


Question: In which war did the Sack of Badajoz takeplace?

Answer: siege of badajoz


Question: In heraldry, what name is given to a diamond shape?

Answer:
rhombus