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

Ex Input:
customer: Hi, I am Jack Lewis. 
 agent: Hello, how may I aid you? 
 customer: Owing an emergence, I want to cancel my recent reservation. 
 agent: Sure, I will help you. 
 customer: Can you please help me with it? 
 agent: Please wait for a while. 
 customer: Ok. 
 agent: Thanks for your time. There is no active reservation found in your name to cancel. 
 customer: No problem, thanks for the information. 
 agent: Thank you for availing us.

Ex Output:
no_reservation


Ex Input:
customer: Hello. 
 agent: Hello! tell me how may I help you? 
 customer: Can you help me to change my existing reservation? 
 agent: OK, can you please tell me your name ? 
 customer: Yes, my name is William Thompson. 
 agent: Sorry, William  no reservation found on your name. 
 customer: Ok, thank you. 
 agent: Thank you.

Ex Output:
no_reservation


Ex Input:
customer: Hello. 
 agent: Hello, how may I assist you? 
 customer: I need your help to book a flight ticket on 11/18 and 11/20. 
 agent: OK, may I know your origin and destination airport codes? 
 customer: Sure, my origin code is NC-CLT and destination code is CA-SFO. 
 agent: Sorry, unfortunately there is no flight in these travel dates. 
 customer: OK, that's fine. 
 agent: May I know your name please? 
 customer: Sure, I am John Thomas. Thank you. 
 agent: Thank you, have a good day.

Ex Output:
no_flight