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: Consider Input: customer: Hello, I am George Baker. 
 agent: Hello, how can I aid you? 
 customer: I would like to attend a meeting with my client at Washington, IAD. Can you please help me in booking on 12/14 and 12/16? 
 agent: Sure, may I know your source airport? 
 customer: My source point is Denver, DEN. 
 agent: Let me know your connection limit. 
 customer: I need a connected flight. 
 agent: Sorry, no flights found with your given dates. 
 customer: Ok, no problem. Thank you. 
 agent: Thank you for choosing us.

Output: no_flight


Input: Consider Input: customer: Hello. 
 agent: Hello, how may I serve you today? 
 customer: I planned to meet my friend in DFW, can you please help me to book a flight ticket from OAK? 
 agent: Sure, can I know your good name please? 
 customer: I am Eric Williams. 
 agent:  When you are willing to travel? 
 customer: I prefer to travel on Apr 27 and Apr 29. 
 agent:  Would you let us know if you have any other preferences? 
 customer: I prefer to travel in a connecting flight. 
 agent: We found a connecting flight 1005 in JetBlue airlines at the cost of 200 with economy class. Can I proceed for booking? 
 customer: Ok, please confirm my booking. 
 agent: Your booking is done. 
 customer: Thank you for your help. 
 agent: Thank you for choosing us.

Output: book


Input: Consider Input: customer: Hello. 
 agent: Hello, how may I help you at present? 
 customer: Can you please help me to change my reservation to other dates? 
 agent: Sure, I am here to help you to change it. 
 customer: Thank you. 
 agent: May I know your name please? 
 customer: Sure, my name is Jerry Hill. 
 agent: Ok, please wait for a moment. 
 customer: Sure. 
 agent: Sorry to say that, there was no reservation found on your name to change it. 
 customer: No issues, thank you. 
 agent: Thank you for reaching our service.
Output: no_reservation