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. 
 customer: I need to reserve my ticket from ATL to LAS. Can you please help me with booking? 
 agent: How can I assist you today? 
 customer: Thank you for considering my request. 
 agent: Sure, can you share me your travelling dates? 
 customer: I want to start my journey on Nov 20 and return back on Nov 22. 
 agent: Do you have any airline preference? 
 customer:  No, I ok with any airlines. 
 agent: Is there any other specifications? 
 customer: No, I din't have any other specifications. 
 agent: I need to know your name for booking a flight ticket? 
 customer: My name is Donald Collins. 
 agent: I found a flight with the price of 300 and 02 connections. Can I proceed to booking? 
 customer: I need to book my ticket in business class and the connection limit is 0. 
 agent: Sorry, no flights are found with 0 connection limit. 
 customer: Ok, no problem, anyway thank you for the information. 
 agent: Thank you for reaching us.
Output:
no_flight