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

Example Input: customer: Hello. 
 agent: Hello, how can I aid you? 
 customer: I am a magician, I have to host a show at Philadelphia. Could you book my ticket from Denver? 
 agent: Sure, may I know your trip dates? 
 customer: My itinerary dates are Nov 21 and Nov 23. 
 agent: Can you please share your region airport codes? 
 customer: My genesis and terminus airport codes are DEN and PHL. 
 agent: Do you have any connection limit preference? 
 customer: No. 
 agent: Do you have any other specifications? 
 customer: I want to depart from Denver in the afternoon. 
 agent: Could you help me with your name please? 
 customer: Anthony Perez here. 
 agent: I found a connecting flight with Southwest Airlines and the airfare is about 100. Shall I proceed with flight 1013? 
 customer: Please proceed. 
 agent: For a economy class flight your ticket is booked. 
 customer: Thank you. 
 agent: Thank you for reaching us.
Example Output: book

Example Input: customer: Hello. 
 agent: Hello, How can I assist you? 
 customer: I am Pamela Martinez. 
 agent: May I know your travelling details? 
 customer: Actually I need to cancel my reservation. Can you please help me? 
 agent: Sure, Please wait a minute. 
 customer: OK. 
 agent: Sorry, No reservation found on your name. Thank you for choosing us. 
 customer: Its k cool. Thank you.
Example Output: no_reservation

Example Input: customer: Hello, I am Lisa harris. 
 agent: Hello, How may I assist you? 
 customer: I want to attend a cultural exhibition in MA - BOS on 09/15 from IL - ORD and return on 09/17. Can you please help me out in booking a ticket with price limit of 5000? 
 agent: Sure. Give me some moment to check the availability of flight? 
 customer: OK. 
 agent: Thank you for being patience. There is a flight available based on your availability. Frontier air lines,flight number 1025. 
 customer: Can I know the price of the flight? 
 agent: Sure. The price is 100. Shall I proceed for booking? 
 customer: OK, you can proceed for booking. 
 agent: OK. Your ticket has been booked successfully. 
 customer: Thanks for your response. 
 agent: Thank you for choosing us!.
Example Output:
book