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: I didn't find any events on Thursday after 7:30 PM.
Example Output: agent

Example Input: I've changed "Appointment" to be for 2 hours and 30 minutes.
Example Output: agent

Example Input: Can you rename it to football game?
Example Output:
user