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.

How many 10 cards are in a deck of 52 cards?
4

Who does the voice of doofenshmirtz on phineas and ferb?
Daniel Kingsley Povenmire

Which military action led to us boycott the 1980 olympics?

Soviet invasion of Afghanistan