You will be given a definition of a task first, then some input of the task.
You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Sentence1: The booking was successful and your reference number is: SQ1LQGMU . Is there anything else I can assist you with. Sentence2: Can you please provide me the entrance fee, phone number and address of a contemporary art museum in the centre of town? Sentence3: Broughton House Gallery is located at 98 King Street. Is there any other information you need? Sentence4: broughton house gallery museum is free and their phone number is 122 331 4960. Sentence5: There are 23 museums in the area. Do you have a particular part of town you are interested in? Sentence6: Yes, they have. Goodbye! Sentence7: Nope. I think I'm all set. Sentence8: yup there is! Sentence9: Is there a suite available for 2 people for 5 nights starting Friday? Sentence10: I'm looking for a popular museum in the area. Sentence11: I am also looking for a hotel called alpha-milton guest house. Sentence12: The alpha-milton guest house is located at 63 milton road postcode cb41xa. The phone number is 01223311625. Would you like me to create a booking? Sentence13: It was my pleasure to help! Have a great day. Sentence14: What is the address of that museum? Sentence15: Thank you for using our service. Have all of your needs been met? Sentence16: I'm interested in the centre of town. Sentence17: Yes I have several. I have contemporary art, anthropology and others. Any type intrigue you? Sentence18: Okay, go ahead and book it and get me a reference number. Question: Who has spoken the sentence 13? (A) User (B) System
Output:
Answer: (B) System