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: Hi. 
 agent: Hello. In which way I can help you at this moment? 
 customer: I need to buy a plane ticket from PHL to OAK. Please help me in that. 
 agent: Sure, I will help you with that. Could you please mention your preferable travel dates? 
 customer: My trip dates are from Aug, 20 to Aug, 22. 
 agent: May I know your name for further process? 
 customer: Anna Robinson. 
 agent: Do you prefer either an economy or business class? 
 customer: I am comfortable with any class. 
 agent: Do you need any specific depart and arrival time for this trip? 
 customer: No. 
 agent: Do you have any another specifications? 
 customer: I need a single connecting flight. 
 agent: Ok, please hold on a moment. 
 customer: Ok. 
 agent: Spirit airline flight available with connection limit 1 and fare is 100, shall I confirm this economy class flight? 
 customer: Please proceed. 
 agent: Your flight ticket is booked successfully, flight number is 1016. 
 customer: Thank you for booking. 
 agent: You are welcome Anna Robinson.
Output:
book