Detailed Instructions: 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
Problem:customer: Hi. 
 agent: Hello, Good Morning. 
 customer: Gary Hill here. 
 agent: How may I guide you? 
 customer: Can you please book me a ticket from PHX to DTW? 
 agent: Sure, can I know your preferable dates? 
 customer: Ok, my preferred travel dates are 04/16 and 04/18. 
 agent: I found a flight 1002 of AA airlines matches with your preferences, can I proceed? 
 customer: Yes, please book it. 
 agent: Your ticket is booked. 
 customer: Thank you for your help. 
 agent: Thank you, have a safe trip.
Solution:
book