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

Example Input: I will decline "trip to Denver". Is that ok?
Example Output: agent

Example Input: Can you reschedule it to the following Thursday?
Example Output:
user