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 may I aid you? 
 customer: Please book a flight ticket from DEN to IAH? 
 agent: May I know your travelling dates? 
 customer: My journey dates are Nov 04 and Nov 06. 
 agent: Is there any connection limit? 
 customer: I need a connecting flight. 
 agent: May I know your good name? 
 customer: I am Carol Harris. 
 agent: Any more requirements? 
 customer: No. 
 agent: Spirit Airlines providing connecting flight in the economy class with fare 100, shall I proceed for booking? 
 customer: Go ahead. 
 agent: Your ticket has been confirmed with flight number 1018. 
 customer: Thank you for your information. 
 agent: Thank you for choosing us.
Output:
book