In this task, you are given an utterance, which is a part of a conversation between a user and an agent. Your job is to detect the speaker. The user usually commands the agent to schedule events, retrieve event information, and check the schedule. While the agent's response is an answer to the user's questions or follow-up questions on the user's command. Answer with "User" or "Agent".

Example Input: Yes. Also change the ending time for the event to 2 PM
Example Output: user

Example Input: OK, when is my next appointment?
Example Output: user

Example Input: The office location of Bill Clinton is White House.
Example Output:
agent