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".

[EX Q]: Is anyone on my team online?
[EX A]: user

[EX Q]: Your Movie Night has been updated to 2 hours and 30 minutes.
[EX A]: agent

[EX Q]: Add to my calendar where am I going? for tomorrow at 5 pm
[EX A]:
user