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: Hi,. 
 agent: Hello, how can I support you? 
 customer: I am Robert Robinson, I want to make a flight reservation to Las Vegas, NV-LAS from Boston MA-BOS. 
 agent: Sure, can you please provide your departure date and arrival date? 
 customer: I would prefer to travel from July 24th to July 26th, with the price limit 1000 and with single connection. 
 agent: OK, please wait for a couple of minutes. 
 customer: Sure,. 
 agent: Thank you for waiting, we are happy to inform you that we have found a flight that matches your requirements. 
 customer: OK, Can I have the details of the flight? 
 agent: Sure, your ticket has been confirmed. Here are the details of your flight, flight number 1027 with flight name Delta and price is 300 and connection limit  is 1. 
 customer: OK, Thank you for your helping hand. 
 agent: Thank you for choosing us,have a good day.
Output:
book