instruction:
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.
question:
When did nigeria become a federation of 19 states?
answer:
1976


question:
Who wrote sitting by the dock of the bay?
answer:
Otis Redding and Steve Cropper


question:
Which nfl head coach has won the most super bowls?
answer:

Bill Belichick