In this task, you are given a context tweet and an answer. Your job is to generate a question for the given answer based on the given tweet paragraph. Note that your question should be answerable based on the given tweet, and the answer to your question should be the given answer.

Context: David Letterman announces that he will retire next year. CBS frantically looking for someone named Jimmy. Albert Brooks (@AlbertBrooks) April 3, 2014 Answer: david letterman
who is retiring next year?