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. 
 customer: I am Larry Turner. 
 agent: How may I address you today? 
 customer: As, there is a food festival is going to be held in Charlotte, CLT so, I want to my food stall in that festival. So, I need your assistance in booking my flight ticket from Boston, BOS. 
 agent: Sure, is there any connection preference? 
 customer: I am comfortable to travel in any flight. 
 agent: Can I know your preferable travelling dates? 
 customer: My schedule dates are 03/24 - 03/26. 
 agent: Please wait a moment I will check and revert to you. 
 customer: Sure. 
 agent: We found a Delta airline matching your details with the connecting flight and the price 200. 
 customer: You can proceed with my booking. 
 agent: Your booking has been confirmed. 
 customer: Thank you for kind service. 
 agent: Thanks for choosing us.
book