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. How may I help you? 
 customer: Can you aid me to book a flight ticket from ATL to CLT? 
 agent: Yes, can you tell me your dates of travel? 
 customer: My trip dates are Nov 17 and Nov 19. 
 agent: Do you have any other preferences? 
 customer: I prefer for connecting flight and return time should be in the morning. 
 agent: Can I know your name for documentation? 
 customer: Nicholas Roberts here. 
 agent: Sorry to inform you that there are no flights found on your requested dates. 
 customer: Thank you. 
 agent: Thank you for contacting us.
Output:
no_flight