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 help you? 
 customer: Being a scientist, I have to give a seminar at Austin, AUS. This is the reason for booking a ticket on 11/23. Will you help me? 
 agent: Sure, I am here to help you. 
 customer: Ok. 
 agent: Can I know your source code please? 
 customer: Book a ticket from Charlotte, CLT. 
 agent: Ok, may I know when you want to return? 
 customer: 11/25 is my return date. 
 agent: Do you need any halt in between your journey? 
 customer: Yes, I need a halt. 
 agent: Wait a minute please. 
 customer: Sure. 
 agent: Thank you for waiting, we found a flight with number 1026 and airline AA at a price of 200 with 1 connection. Shall I proceed? 
 customer: Ok, book my ticket with this flight. 
 agent: Sure, your booking is done. 
 customer: Thank you for your service. 
 agent: May I know your name please? 
 customer: Reserve a ticket with the name of Gary Phillips. 
 agent: Thank you for reaching us, have  a nice day.
Output:
book