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. 
 agent: Hello, how can I assist you? 
 customer: I want to book a flight ticket from SFO to DCA, can you please help me out? 
 agent: Ok, please let me know your dates of journey to book a ticket. 
 customer: My preferable dates are May 7 and May 9 respectively. 
 agent: Ok, please can I know your specifications? 
 customer: I am looking for a economy class flight and a single connecting flight limit. 
 agent: Ok, please can I know if you need anything else? 
 customer: No. 
 agent: Ok, there is a economy class flight with 1 connection limit and the airfare is 100. Can I book a flight 1019? 
 customer: Good to hear, please book for this flight. 
 agent: Ok, please can I know your name to confirm? 
 customer: George Phillips here. 
 agent: Ok, the flight ticket is confirm and the airlines is UA. The depart time is 14:00PM and arrival time is 8:00AM. 
 customer: Thank you for assisting me. 
 agent: Thank you for availing our service, have safe journey.
Output:
book