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 aid you today from end? 
 customer: I am Frank Davis from Boston. Could you please help me in flight ticket booking process from BOS to ATL? 
 agent: Sure  Frank Davis, I am here to help you out. Please provide me your trip dates. 
 customer: Thank you for your response, I want to take off on Apr 22 and please confirm my return ticket also on Apr 24. 
 agent: Please allow me a moment. 
 customer: Ok. 
 agent: Here is a flight with 1 stop and price is 200 in economy class, can I proceed with it? 
 customer: Please confirm this flight ticket for me. 
 agent: Your ticket has been booked with 1010 flight in frontier airlines. 
 customer: Thank you for your help. 
 agent: Thank you for reaching us.
book