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, I am Betty Walker. 
 agent: Hello, how can I assist you today? 
 customer: I am planning to meet my friend in Atlanta, can you please help me to book a flight ticket? Make sure that my price limit is 1000. 
 agent: Sure, can you please provide your journey dates? 
 customer: My travelling dates are from 06/21 to 06/23. 
 agent: How many connections do you need in between journey? 
 customer: I need a flight with single connection. 
 agent: Please mention your source and destination airport codes. 
 customer: I am travelling from NV - LAS to GA - ATL. 
 agent: Ok, please for a couple of minutes. 
 customer: Ok. 
 agent: We are glad to inform you that, we found a flight Delta airlines, flight number 1000, price is 100. 
 customer: Ok, you can proceed with my booking. 
 agent: Ok, your ticket has been reserved. 
 customer: Thanks for your service. 
 agent: Thank you for reaching us. 
 customer: Thank you.
Output:
book