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: Yes, please make reservations. Sentence2: Your reference number is : MUBTUUTM . Can I help with anything else? Sentence3: I have a train TR4068 leaving at 5:35 and arriving at 5:52. Would you like to make reservations? Sentence4: yes please, for 5 people at 20:15 on Thursday. Sentence5: The best time matching your criteria is a departure from Ely at 11:35. Will that do? Sentence6: Yes, there are quite a few. Is there a day and time you would like to travel? Sentence7: I would like to find a cheap mediterranean restaurant in the centre Sentence8: Did you book for 5 people? Is there a train that arrives closer to but before 14:45? Thanks. Sentence9: There is one matching result. It is the gardenia. Do you want me to book something there? Sentence10: I'm looking for a train from Ely to Cambridge. Do you have any? Sentence11: I'm sorry, my travel day is actually Thursday, not Sunday. I need to arrive by 14:45. Sentence12: Thank you for using our services. Sentence13: Yes, leaving on Sunday at 10:00 AM Sentence14: Thank you that will be all. Sentence15: Booking was successful, the total fee is 22 GBP payable at the station . Reference number is : IPO23Y22 . Is there anything else I can help you with? Sentence16: yes with reference number Sentence17: I apologize about that. The closest I can get you there is on train TR4992 which will arrive at 13:52. Would you like me to book it for 5 people? Sentence18: Booking was successful. The table will be reserved for 15 minutes. Reference number is : HWJS11KB . Is there anything else I can assist you with? Question: Who has spoken the sentence 12? (A) User (B) System
Output:
Answer: (A) User