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: How about the rating for Sanctuary in Iowa City?
Example Output: user

Example Input: Friday works perfectly. However change the time to 11:20am-12:40pm please.
Example Output: user

Example Input: Thanks. Do you know Bill Clinton's phone number?
Example Output:
user