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.

Input: Consider Input: Where is the descending aorta located in the mediastinum?

Output: posterior mediastinal cavity


Input: Consider Input: Do zebras have white stripes or black stripes?

Output: black and the white stripes and bellies are additions


Input: Consider Input: When did royal mail and post office split?


Output: 1 April 2012