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: change the dinner with amy time at 9.00 pm
Example Output: user

Example Input: Thanks, add a one hour lunch with Emily at noon tomorrow.
Example Output: user

Example Input: Ok, and what about Miller Union in Atlanta?
Example Output:
user