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: In 550 bc which leader began the persian empire?

SOLUTION: Cyrus II of Persia

PROBLEM: Actress who was oscar nominated for the 1999 film leaving las vegas?

SOLUTION: Elisabeth Judson Shue

PROBLEM: How many ipv4 addresses are there in total?

SOLUTION:
fewer than 4.3 billion