Given the task definition, example input & output, solve the new input case.
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
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.
Output: no_reservation
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

New input case for you: customer: Hello, I am Betty Walker. 
 agent: Hello, how can I assist you today? 
 customer: I am planning to meet my friend in Atlanta, can you please help me to book a flight ticket? Make sure that my price limit is 1000. 
 agent: Sure, can you please provide your journey dates? 
 customer: My travelling dates are from 06/21 to 06/23. 
 agent: How many connections do you need in between journey? 
 customer: I need a flight with single connection. 
 agent: Please mention your source and destination airport codes. 
 customer: I am travelling from NV - LAS to GA - ATL. 
 agent: Ok, please for a couple of minutes. 
 customer: Ok. 
 agent: We are glad to inform you that, we found a flight Delta airlines, flight number 1000, price is 100. 
 customer: Ok, you can proceed with my booking. 
 agent: Ok, your ticket has been reserved. 
 customer: Thanks for your service. 
 agent: Thank you for reaching us. 
 customer: Thank you.
Output:
book