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: Hi. 
 agent: Hello, how may I help you today? 
 customer: Can you please help me in booking a flight ticket to PHX from LAX? 
 agent: Sure, may I know your travel dates? 
 customer: My travel dates are from Apr 22 to Apr 24. 
 agent: Do you need a direct flight or connecting flight? 
 customer: I need a direct flight. 
 agent: May I know your name to proceed further? 
 customer: I am Anna Anderson. 
 agent: Ok, please wait a minute. 
 customer: Ok. 
 agent: We found a direct flight in Delta Airlines with flight number 1005 having an economy class. 
 customer: You can proceed with booking. 
 agent: Your booking has been confirmed. 
 customer: Thank you for your help. 
 agent: Thank you for approaching us.
book