Given the task definition and input, reply with output. 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

customer: Hello. 
 agent: Hello. How may I help you? 
 customer: Would you please help me in booking a ticket from DFW to ATL.  Where I am going  to meet my college mates. 
 agent: Yes, can you tell me your dates of travel? 
 customer: My itinerary travel dates are as follows Nov 18 and Nov 20. 
 agent: Do you have any preferences? 
 customer: I would like to board a single connecting flight where the class should be of business. 
 agent: Give me a moment. 
 customer: And depart time should be in the afternoon. 
 agent: Sorry to inform you that there are no flights found on your requested dates. 
 customer: No issue, thank you for the information. 
 agent: Can I know your name? 
 customer: Jennifer Smith. 
 agent: Thank you for contacting us.
no_flight