You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.

Ex Input:
Sentence1: Okay, the TR8944 leaves at 15:39 and arrives by 17:07. Would you like me to book tickets for you? Sentence2: There are 10 trains leaving fro Liverpool Street on Thursday. Did you have a departure time in mind? Sentence3: Okay I have booked you and your reference number is WLUOQKEV . Sentence4: rosa's bed and breakfast is in the cheap price range Sentence5: I'm looking for a train departing from london liverpool street leaving on thursday. Sentence6: Do you need a taxi? Sentence7: Goodbye, and thanks again. Sentence8: Yes, I don't want to leave for Cambridge until 15:00 at the earliest. Sentence9: Sure thing. Thanks for letting us help you today! Sentence10: Thank you. I also need a hotel in the south. Sentence11: then thanks for inquiring with us. Sentence12: I don't need a taxi, thanks for asking Sentence13: No price range but I do want a 4 start. Sentence14: Yes, for 6 people. Sentence15: What price range are you interested in? Sentence16: That sounds great. I'll need a reservation for 6 people for 4 nights on Thursday. Sentence17: I've gone ahead and booked that for you. Your Reference number is : EUZ34KY9 . Is there anything else I can assist you with today? Sentence18: No, that takes care of everything I need. Thanks! Question: Who has spoken the sentence 7? (A) User (B) System

Ex Output:
Answer: (B) System

Ex Input:
Sentence1: Thank you so much. That is all I will need today. Sentence2: Great, how many tickets would you like to purchase? Sentence3: That would be perfect! Sentence4: I am looking to go from cambridge, and go on friday arriving by 14:30 Sentence5: Okay, how about the TR5901 leaving at 13:34 and arriving at 14:24 with a duration of 50 minutes? The cost is 16.50 pounds. Would that work for you? Sentence6: There are 266 trains going to Peterborough. Can you give me a departure day and time so that I can narrow down your choices? Sentence7: Your tickets are all booked, reference number R5P65TW5 Sentence8: I'd like to find a train to peterborough. Sentence9: Thank you for contacting Cambridge TownInfo centre. Have a wonderful day! Sentence10: 7 tickets please. Can I also have the reference number for the booking? Question: Who has spoken the sentence 4? (A) User (B) System

Ex Output:
Answer: (A) User

Ex Input:
Sentence1: Ok great! I was able to get you booked, your reference number is N4TJE8VR . Is there anything else that I can help you with? Sentence2: Yes please. There are 5 of us total and we need 4 nights in a row. Thank you. Sentence3: May I get your departure and destination information please? Sentence4: Can you verify the cost for train TR6954 for me? Sentence5: There don't seem to be any 5-star lodgings in the city. Would you like to try searching for 4 stars instead? Sentence6: I am looking for a train arriving by 9:45 on Tuesday. Sentence7: I'd like to start my stay on Tuesday, please. Sentence8: Your booking reference is NT43PSC0 . Now, if you let me know what type of hotel you are interested in, I can help you with that as well. Sentence9: TR6954 departs from Leicester at 07:09 and arrives in Cambridge at 08:54. Would you like to book this train? Sentence10: What day would like to start your stay? Sentence11: Maybe... how much does it cost? Sentence12: Yes, 4 stars would be fine. Sentence13: Nope, that'll take care of everything, thanks! Sentence14: I am going from Cambridge to Leicester. Sentence15: I'm sorry, we have that mixed up. I need to depart from leicester and go to cambridge. Do you have a train that arrives by 09:45 in cambridge? Sentence16: The acorn guest house is a 4 star hotel located in the north side. Would you like to make reservations? Sentence17: You're welcome. Have a great stay! Sentence18: TR2863 departs from Cambridge at 07:21 and arrive in Leicester by 09:06. Would you like to book this train? Sentence19: Yes I would like help with booking the train and I will also need to book a hotel. Sentence20: It costs 37.80 pounds per ticket. Sentence21: The cost for this particular train is 37.80 pounds per ticket. Would you like assistance booking tickets for this train? Sentence22: Can you help me find a 5-star room somewhere that offers free parking and wifi? Question: Who has spoken the sentence 17? (A) User (B) System

Ex Output:
Answer: (B) System