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: Commander Shepard, Jacob Taylor, Miranda Lawson, Thane Krios, Grunt, Jack, Mordin Solus, Samara, Morinth, Legion, Zaeed Messani, Garrus Vakarian and Tali'Zorah Vas Neema are characters in which computer game?

Output: commander shepard, miranda lawson, mordin solus, samara, legion