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, I am Shirley Campbell. 
 agent: Hello, how may I help you at this moment? 
 customer: I would like to go to visit Statue of Liberty in New York, so could you please book a ticket for me? 
 agent: Surely, I will help you. Can I have your travelling dates? 
 customer: Sure, I would like to go on 10/31 and return back on 11/02. 
 agent: Please provide your source and destination airport codes respectively. 
 customer: My source and destination airport codes are MSP and JFK. 
 agent: Please hold on for a moment. 
 customer: Ok, ensure it is a single connecting flight. 
 agent: Thank you for waiting Shirley, there is a 1 connection flight available with Delta airline. Shall I book it? 
 customer: Ok, please proceed for further if it costs you below 1000. 
 agent: Your booking is done with flight number 1000. Happy journey. 
 customer: Thank you for booking. 
 agent: You are welcome. Thank you for reaching us, have a nice day. 
 customer: Welcome.
book