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.

Example Input: What are freshmen called at the air force academy?
Example Output: Fourth class cadets

Example Input: What is wrong with april kepner's baby on grey's anatomy?
Example Output: Osteogenesis Imperfecta type 2

Example Input: What is the maximum length of phone number?
Example Output:
15 digits