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

Example Input: customer: Hi. This is Michelle Clark, from Dallas. 
 agent: Hello, How may I assist you? 
 customer: Recently I made a reservation and now the trip has been postponed due to some issues. Can you help me in changing my ticket? 
 agent: Sure, I can help you. 
 customer: Thank you. 
 agent: Please wait for a while. 
 customer: Sure. 
 agent: Thanks for your time, there is no reservation found in your name. 
 customer: That's ok, not an issue. Thanks for your effort. 
 agent: Thank you for choosing us.
Example Output: no_reservation

Example Input: customer: Hello. I am Dennis Anderson. 
 agent: Hello, how may I aid you today from my end? 
 customer: I want to change my reservation, due to some health issue. Can you please help me out? 
 agent: Sure, I am here to help you out. Please allow me a moment. 
 customer: Ok, I will wait for your information. 
 agent: Sorry Dennis Anderson, there is no reservation on your name in our database. 
 customer: That's ok, thank you for checking. 
 agent: Thank you for reaching us.
Example Output: no_reservation

Example Input: customer: Hello. 
 agent: Hello. 
 customer: I am Angela Baker. 
 agent: How may I aid you today? 
 customer: Can you find a flight from HOU to SEA, to visit the Chihuly Garden and Glass. 
 agent: Sure, I am here to help you out. Please provide me your trip dates. 
 customer: Help me with booking ticket from 08/20 and 08/22. 
 agent: Sure  Angela Baker, there is a flight with 1 stop and price is 100 in economy class, can I proceed with it? 
 customer: Yes, please. 
 agent: Your ticket has need with 1014 flight in Delta airlines. 
 customer: Thanks for your help. 
 agent: Thank you for reaching us.
Example Output:
book