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
Q: customer: Hello. 
 agent: Hello, How can I assist you? 
 customer: I am Betty Lewis. Please book a ticket from CLT to ATL? 
 agent: Sure, May I know the travelling dates? 
 customer: My travel dates are Jul 13 and Jul 15 respectively. 
 agent: Do you have any class preference? 
 customer: I would like to travel in the morning. 
 agent: Do you have any connection limit? 
 customer: No other specifications. 
 agent: Please wait a minute. 
 customer: Ok. 
 agent: Sorry, No flights found with your chosen dates. 
 customer: Thank you for information. 
 agent: Thank you for opting us.
A:
no_flight