Definition: 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 assist you? 
 customer: I want to attend my brother wedding, could you please book my ticket? 
 agent: Ok, help me with the travelling details. 
 customer: I would like to move from EWR on 11/13. 
 agent: Can I know the destination code with date? 
 customer: My destination airport code is IAH and return date on 11/15. 
 agent: May I know your name? 
 customer: Sure, my name is Stephen Hill. 
 agent: There is a flight with airline Southwest and fare is 200. Can I book it? 
 customer: Ok, please book my ticket. 
 agent: Your ticket is booked with number 1007. Have a safe flight. 
 customer: Thank you for helping me.
Output:
book