TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Who played the title role in the 1955 film 'Davy Crockett, King Of The Wild Frontier'?

SOLUTION: davy crockett

PROBLEM: Who painted The Card Players, at Feb 2012 the most expensive artwork in the world?

SOLUTION: the card players

PROBLEM: Who had number 1 hits in 1959 with 'Dream Lover' and 'Mack the Knife'?

SOLUTION:
mack the knife