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: How about the same day at 12:30? If that works, please send the reference number. Sentence2: Thank you very much for your help. Sentence3: Okay! Thank you for calling. Sentence4: Unfortunately we cannot book at that time, could you choose another day or time please? Sentence5: I need the train to leave on Sunday. Sentence6: Okay, I got one leaving at 5:17 and another at 7:17, do you have a preference? Sentence7: No, that was everything, thank you! Sentence8: I want to book the reservation the same day as my train at 13:30 for 8 people. Sentence9: I can book you on train number TR4543. It departs at 07:17 and arrives in Cambridge at 8:08. Sentence10: I'd like to depart from London kings cross Sentence11: 7:17 please. I would like to book for 8 people and i need the reference number. I would also like to book at Bangkok City restaurant. Sentence12: There are 231 trains that arrive in Cambridge before 8:45, can you tell me where you want to depart from to narrow it down? Sentence13: okay is there anything else i can help you with? Sentence14: I would like a ticket to a train that arrives in Cambridge before 8:45am. Sentence15: No, my mistake. Thank you. Sentence16: It works. The reference number is YRIP8V3C . Anything else I can do for you? Sentence17: You would like an additional reservation at Bangkok city restaurant? Sentence18: i would also like to book a reservation at bangkok city. Sentence19: Good day then. Sentence20: I've booked the train. Your reference number is YRIP8V3C . For what day and time would you like the restaurant reservation? Question: Who has spoken the sentence 1? (A) User (B) System
Output:
Answer: (B) System