Definition: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: book it for 2 people and 4 nights starting from tuesday. Sentence2: You are welcome. Have a good visit. Thanks for using the TownInfo centre. Goodbye. Sentence3: The alpha-milton guest house is in the north part of town at 63 milton road. Sentence4: No thank you! Sentence5: I have successfuly booked the hotel for you. Your reference number is 1XPV9OMK . Is there anything else I may help you with? Sentence6: I am looking for a hotel called alpha-milton guest house Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User