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: Add a team meeting on Tuesday at 3:00 PM.
Example Output: user

Example Input: Actually move "Trial by Fire" to Monday on the 27th.
Example Output: user

Example Input: Nava
Example Output:
user