TASK DEFINITION: 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.
PROBLEM: Who is the original singer of nothing compares to you?

SOLUTION: Prince Rogers Nelson

PROBLEM: Journal of optics a pure and applied optics abbreviation?

SOLUTION: J. Opt.

PROBLEM: Jack ryan season 1 has how many episodes?

SOLUTION:
8