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 assist you today? 
 customer: I have planned to go for Cultural festival at Detroit, DTW. Can you please help me for booking? 
 agent: Sure, I'm happy to help you in that. May I know your source airport code please? 
 customer: Sure, my source airport code is HOU. 
 agent: Can you please provide your planned travel dates? 
 customer: My travelling dates are Feb 11 and Feb 13. 
 agent: Can I have your good name please? 
 customer: Sure, I am Kevin Clark. 
 agent: Ok, please wait for a while. 
 customer: Ok. 
 agent: Delta airlines is having a flight on that route with ticket fare of 100, shall I proceed for booking? 
 customer: Ok, please confirm. 
 agent: I have successfully booked your ticket with flight-1002, have a safe journey. 
 customer: Thank you. 
 agent: Thank you for choosing us.
Output:
book