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

Ex Input:
Chris Martin is the lead singer with which band who had several hits in the 2000s?

Ex Output:
chris martin


Ex Input:
In which film of 1995 did Robert De Niro and Al Pacino appear on screen together for the first time?

Ex Output:
al pacino


Ex Input:
Which German social economist of Jewish descent, expelled from Germany and France, co-wrote in London The Communist Manifesto and Das Kapital?

Ex Output:

the communist manifesto