You will be given a definition of a task first, then some input of the task.
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

customer: Hello. 
 agent: Hello, how can I aid you? 
 customer: I am planning to visit Houston, can you please book me a ticket from DEN to HOU? 
 agent: Sure, please share your trip dates. 
 customer: My planned dates of journey are Feb 27 and Feb 29. 
 agent: May I know your connection limit? 
 customer: I prefer connecting flight for this trip. 
 agent: Which class do you prefer? 
 customer: I am comfort with any class. 
 agent: May I know your name? 
 customer: My name is Stephanie Carter. 
 agent: Please wait for a while. 
 customer: Sure. 
 agent: UA airlines with flight 1002 is providing a connecting flight and ticket costs you 300 in economy class. 
 customer: Please reserve my ticket in this flight. 
 agent: Your ticket is confirmed Stephanie Carter. Flight departs at 13:00 hours and arrives at 0:00 hours. 
 customer: Thank you for booking my ticket. 
 agent: Thank you for reaching us.
Output:
book