In this task, you are given a conversation between a flight agent and the customer. You are given 4 options and you need to select the goal of the conversation. It is provided as part of customer's context, which has to be one of the following: `book`: Make a new reservation, `cancel`: Cancel an existing reservation, `no_flight`: No flight found for the customer's preference, `no_reservation`: No reservation / No change / No cancellation was made in the conversation, mostly enquiring details

Example input: customer: Hi. 
 agent: Hello. How can I help you? 
 customer: I would like to change my existing reservation as my plan to go for a holiday trip got postponed. Can you please help me with this? 
 agent: Sure, may I know your name please? 
 customer: My name is Anthony Phillips. 
 agent: Please wait a moment. 
 customer: Sure. 
 agent: Unfortunately there is no reservation found with your given name. 
 customer: Not a problem, thank you for checking. 
 agent: Thank you for choosing us.
Example output: no_reservation
Example explanation: Here the customer has not asked for any booking, he just wanted to update his already booked flight, so the status would be no_reservation
Q: customer: Hello. 
 agent: Hello, how may I support you? 
 customer: Assist me in booking a flight ticket from SFO to DEN. 
 agent: I can definitely do that for you. Will you please let me know your maximum connection limit? 
 customer: Single connection flight is required. 
 agent: On what dates are you planning to make your trip? 
 customer: I preferred to travel in June 23 and June 25. 
 agent: Which airline will you prefer to travel in? 
 customer: I prefer to travel in normal cost airline. 
 agent: Do you need an economy class or business class? 
 customer: Economy class suits best to me. 
 agent: Please forward your name. 
 customer: This is Samantha Lewis. 
 agent: We found a direct flight on your way. Is that fine? 
 customer: Sure, proceed to book it. 
 agent: Your booking has been done in flight 1012 of United airlines with an estimate of 200. 
 customer: Thanks for your booking. 
 agent: Thank you for reaching us.
A:
book