In this task, you're given an open-domain question. Your task is to provide an answer to the given question. There is only one unique answer for each question. Your answer should be short, and refer to an entity, date, number, etc. Do not put your answer in the context of a sentence.

Ex Input:
When did nigeria become a federation of 19 states?

Ex Output:
1976


Ex Input:
Who is the female guitarist in this is it?

Ex Output:
Orianthi Penny Panagaris


Ex Input:
Who wrote the pathbreaking book on pollution titled silent spring?

Ex Output:

Rachel Carson