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 Jack Perez. 
 agent: Hello. How can I help you? 
 customer: I would like to visit Statue of Liberty in New York, so could you please book a ticket for me? 
 agent: Sure. I will help you to book a flight, can you please provide me your travelling dates? 
 customer: Sure, I would like to go on 11/09 and return back on 11/11. 
 agent: Ok, please share me your travelling airport codes. 
 customer: My source and destination airport codes are ORD and LGA. 
 agent: Give me a moment. 
 customer: Ok, ensure it is a single connecting flight. 
 agent: Sorry, there is no flight is found on your route with single connection. 
 customer: That's ok, thank you for checking. 
 agent: Welcome. Thank you for choosing us.
no_flight