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. 
 agent: Hello, what can I do for you at this time? 
 customer:  I am Kimberly Hill. I want to book a ticket to NY-LGA from TX-AUS. 
 agent: Sure, can I know your dates? 
 customer: My travelling dates are 09/23 and 09/25. 
 agent: Just hold on for a moment. 
 customer: Ok. 
 agent: Sorry for the inconvenience, there is no flight available on your dates. 
 customer: Ok, thank you for you response. 
 agent: Thank you for opting us.

Output: no_flight


Input: Consider Input: customer: Hello. 
 agent: Hello, how may I help you? 
 customer: Can you please help me in booking a flight ticket from Denver, DEN to Phoenix, PHX? 
 agent: Sure, help me with the trip dates? 
 customer: My journey dates are from Aug 15 to Aug 17. 
 agent: Do you have any specifications to be met? 
 customer: No. 
 agent: May I know your name for the documentation purpose? 
 customer: My name is Kevin Harris. 
 agent: We found a flight in an airline Hawaiian with 1026 number having a single connection in an economy class. Shall I proceed to book? 
 customer: Sure, you can proceed for booking. 
 agent: Your flight ticket has been confirmed. 
 customer: Thanks for your help. 
 agent: Thank you for opting us.

Output: book


Input: Consider Input: customer: Hello, Jerry Young here. 
 agent: Hello, how can I serve you? 
 customer: I want to alter my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please take your some time for helping me? 
 agent: Sure. Please wait a while. 
 customer: Ok. 
 agent: Sorry, there is no reservation under your name. 
 customer: Ok, thank you for the information. 
 agent: Thank you for reaching us.
Output: no_reservation