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]: When is the meeting with the lecture?
[EX A]: user

[EX Q]: Extend it by another 15 minutes.
[EX A]: user

[EX Q]: Delete my meeting with Karl and Keri next week as well.
[EX A]:
user