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
Input: customer: Hello. 
 agent: Hello. How can I help you? 
 customer: My name is Gary Jones. I want to attend my sister's marriage in Phoenix, could you please help me in booking a flight ticket? 
 agent: I'm glad to help you. Please provide me your airport codes. 
 customer: It's from SEA to PHX. 
 agent: May I know your travel dates? 
 customer: The dates are from 09/13 to 09/15. 
 agent: Please wait a minute. 
 customer: Ok. 
 agent: There is a flight available with price 200 from Frontier airlines. Would you like to proceed with this flight? 
 customer: That's perfect. Please book the ticket. 
 agent: Your ticket has been booked. 
 customer: Thank you for your help. 
 agent: Thank you for choosing our services.
Output:
book