Instructions: You are shown a conversation between a user and system. Identify who has spoken the indicated sentence based on the conversation.
Input: Sentence1: I'm looking for a cheap hotel. Sentence2: That is all for today. Thank you. Sentence3: I'm sorry, that time is not available. Can we try a short length of stay or different day? Sentence4: Yes, I was able to book that. The reference number is U0JT0YZ8 . DO you need anything else? Sentence5: No problem. I'm glad I could help. Sentence6: Actually, you mentioned its in the east. I really prefer something in the centre of town thats cheap and 4-star rated. It can be a guesthouse or hotel. Sentence7: The Alexander Bed and Breakfast is a cheap 4 star guesthouse in the centre of town. Would you like me to book it for you? Sentence8: Are you sure the Alexander is in the centre? You said earlier that it's in the east. Sentence9: alexander bed and breakfast is a guesthouse east of Cambridge center that is cheap, would you like more information? Sentence10: Can you see if they have just 2 nights available? Sentence11: Yes. I'm travelling with my family, so I need a room for 7 people for 4 nights, arriving Thursday. Sentence12: Sorry, that booking was unavailable. Perhaps you'd like a different day or a shorter stay? Sentence13: Does it have a star of 4. I don't care if it has free parking. Sentence14: Yes, it's in the centre. Sentence15: Alexander bed and breakfast does have a 4 star rating, would you like help to book a room? Sentence16: Please double check and make sure the booking is good. Question: Who has spoken the sentence 5? (A) User (B) System
Output:
Answer: (B) System