Given an trivia question precisely answer the question with a word/phrase/name. External resources such as Wikipedia could be used to obtain the facts.

Ex Input:
Three of the Galilean moons of Jupiter are Io, Europa and Callisto. Which is the fourth?

Ex Output:
ganymede


Ex Input:
Which of the wives of Henry VIII was born in Madrid in 1485?

Ex Output:
catherine of aragon


Ex Input:
'Janus' was discovered in 1966.It is a moon of which planet?

Ex Output:

saturn