Instructions: 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
Input: customer: Hello. 
 agent: Hello, how can I amend you today? 
 customer: I am Betty Nelson, I want to book a flight to Chicago for vacation for few days. Can you book a flight on 01/01? 
 agent: Sure, may I know your return date? 
 customer: I will return on 01/03. 
 agent: Ok, kindly mention your journey airport codes. 
 customer: I will fly from CA-LAX to IL-ORD. 
 agent: Ok, do you need any halt in between your journey? 
 customer: Yes, I need a halt in between the journey. 
 agent: Thanks for being patient, there is a flight found in 1009 UA airline with a fare of 100. Shall I proceed? 
 customer: Sure, you can proceed. 
 agent: Sure, your booking has been done. 
 customer: Thank you for helping me. 
 agent: Thank you for approaching us.
Output:
book