Definition: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: That was all I needed. Sentence2: What area of town interests you most ? Sentence3: Yes, I would like to arrive by 20:15. Sentence4: Your ticket has been booked. Your reference number is 561MGK3J. Is there anything else I can do for you? Sentence5: i also want a train to take me to ely Sentence6: Any area is fine, as long as the place has free wifi. Sentence7: TR7355 arrives in ely by 18:07, or there is also one that arrives by 20:07. Would you like to book a ticket for one of these? Sentence8: Yes, I will also need free parking. Sentence9: Yes please. I need one ticket. Sentence10: Done! Your reference number is WTJER271 . Can I help you with anything else? Sentence11: Thank you for contacting us and have a nice day. Sentence12: Will you need free parking as well? Sentence13: Just check moderate price range then please! Sentence14: There are no hotels in the moderate price range with a 4 star rating. Is there another price range or star rating that you would like me to check? Sentence15: I would like my reservations to start on sunday. Sentence16: Ok! There are 10 trains; do you have a time preference? Sentence17: On what day do you need to go to Ely? Sentence18: Find me a place to stay. I need a hotel in the moderate price range with a star of 4. Sentence19: Thursday, please. I need to leave from Cambridge. Sentence20: We have the Ashley Hotel and Lovell Lodge that fit what you want, would you like me to book one for you? Sentence21: What day would you like you stay to start? Sentence22: Yes just for me. For four nights please Question: Who has spoken the sentence 4? (A) User (B) System
Output:
Answer: (A) User