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 need you to block off 6 hours starting at 7PM tomorrow for the Fall Out Boy Concert.
Example Output: user

Example Input: That's it!
Example Output: user

Example Input: Decline training with Ted for the tournament this week.
Example Output:
user