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: Dorothy Hill here. I want to reserve a ticket from JFK to DEN, could you help me in doing that? 
 agent: Sure, I am gleeful to help you. Could you please provide your travelling dates to search for the flight? 
 customer: My trip dates are Sep 05 to 07. 
 agent: May I know your preferable journey timings? 
 customer: I want to return in afternoon time. 
 agent: Do you have any requirements? 
 customer: I need a connecting flight. 
 agent: There is a connecting flight 1005 of UA airlines, can I proceed? 
 customer: Ok, please proceed. 
 agent: Your booking is done in economy class. 
 customer: Thank you. 
 agent: You are welcome.
book