Definition: 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, I am Susan White. 
 agent: Hello. How can I help you? 
 customer: Can you please help me to book a ticket from ATL to SFO? 
 agent: Your travelling dates please? 
 customer: My travelling dates will be on Aug 9 to Aug 11. 
 agent: Do you have any specifications? 
 customer: I need a connecting flight. My depart time should be evening. 
 agent: Here is a connecting flight with flight number 1017 and fare is 200, providing ticket in economy class and your departure time is 2:00 AM. Shall I proceed with booking? 
 customer: You can proceed. 
 agent: Your booking  is done Delta airlines. 
 customer: Thank you for your help. 
 agent: Thank you for choosing us.
Output:
book