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

Let me give you an example: customer: Hi. 
 agent: Hello. How can I help you? 
 customer: I would like to change my existing reservation as my plan to go for a holiday trip got postponed. Can you please help me with this? 
 agent: Sure, may I know your name please? 
 customer: My name is Anthony Phillips. 
 agent: Please wait a moment. 
 customer: Sure. 
 agent: Unfortunately there is no reservation found with your given name. 
 customer: Not a problem, thank you for checking. 
 agent: Thank you for choosing us.
The answer to this example can be: no_reservation
Here is why: Here the customer has not asked for any booking, he just wanted to update his already booked flight, so the status would be no_reservation

OK. solve this:
customer: Hello, myself David Baker. 
 agent: Hello. How may I help you for the day? 
 customer: I want to change my destination airport codes in my existing reservation, can you please help me out? 
 agent: Please wait a  moment, let me check with your details. 
 customer: Ok, I will wait for your response. 
 agent: Please provide me you trip details. 
 customer: My planned trip dates are 10/08 and 10/10. 
 agent: Can you please provide your airport codes which you are travelling. 
 customer: Sure, my location airport codes are PHX and DCA. 
 agent: There is a flight available with one connection and the price is 200, can I proceed with that?'. 
 customer: Fine, please reserve me a seat. 
 agent: Your ticket has been booked with the Sprint airlines and the flight number is 1002. 
 customer: Thank you for your quick service. 
 agent: Thank you for reaching us.Have a safe journey ahead.
Answer:
book