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:
Where do purple martins go for the winter?
answer:
Amazon River Basin


question:
Who won the 2014 world cup that was held in brazil?
answer:
Germany


question:
What is a period of 3 years called?
answer:

Triennium