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

Positive Example 1 -
Input: Who was the first American President?
Output: president of the united states

Positive Example 2 -
Input: The Dutch duo of Ray Slijngaard and Anita Dels, who had 8 top ten hits in the 90s, were better known by what name?
Output: anita doth

Negative Example 1 -
Input: Anna Smashnova played which sport professionally until 2007?
Output: sport

Negative Example 2 -
Input: Rob Davis, Les Gray, Dave Mount and Ray Stiles are members of which pop group?
Output: david

Now complete the following example -
Input: In 1965, which American pop group, whose original members include the legendary David Crosby, had a No.1 hit with the Bob Dylan song, Mr Tambourine Man?

Output: bob dylan, mr. tambourine man