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: Hi. 
 agent: Hello. How can I help you? 
 customer: Can you please help me with booking a flight ticket from DFW to LAS? 
 agent: Sure,  I will help you. Can I know your good name? 
 customer: My name is Susan Moore. 
 agent: May I know your depart date and arrival dates? 
 customer: My travel dates are Mar 27 and 29. 
 agent: Let me know your connection limit. 
 customer: I need a connecting flight. 
 agent: Do you have any preferences? 
 customer: I prefer business class. 
 agent: Please, wait a minute. 
 customer: Ok. 
 agent: I am sorry, there were no flights available that matches your requirements. 
 customer: Ok, no issues. 
 agent: Thank you for approaching us. 
 customer: Thanks for the help.
Output:
no_flight