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

Example Input: Which singer/songwriter, who began releasing hit singles in 1958, has had 3 albums (The Definitive Collection, Waking Up Is Hard to Do & The Music of My Life) on Billboard's Top 200 Albums chart between 2007 & 2010?
Example Output: the definitive collection

Example Input: The plays 'The Barber of Seville' and 'Marriage of Figaro' were written by whom?
Example Output: the marriage of figaro

Example Input: In which European city is the Atomium?
Example Output:
atomium