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: Hi, I am Katherine Lewis. 
 agent: Hello, how may I help you. 
 customer: Can you please help me with booking a flight ticket from BOS to CLT? 
 agent: Sure, let me know your preferable dates? 
 customer: Travel dates are 09/23 and 09/25. 
 agent: Sorry, there are no flights found on given schedule. 
 customer: Ok, no issues. 
 agent: Thank you for reaching us. 
 customer: Thanks for the help.
A:
no_flight