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 between December 24th and December 31st.
Example Output: agent

Example Input: When is the physics lab report due?
Example Output: user

Example Input: Make a meeting with Jeff on Thursday at 2:30 pm in the spare room.
Example Output:
user