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 be a help for you? 
 customer: I'm Debra Mitchell. I am planning to attend live music concert at Detroit, DTW.Can you please help me with booking a flight ticket from DTW? 
 agent: Sure, I will help you. 
 customer: Thank you. 
 agent: Can you please share your preferable dates to travel? 
 customer: Sure, I would like to take off on 07/31 and return back on 08/02. 
 agent: As per your request, there is a flight available in this route from Frontier airlines with 1 connecting flight. Do you like to travel in this airlines? 
 customer: Yes, please proceed with the booking if the price limit does not exceed 1000. 
 agent: Your ticket is booked successfully with flight 1020. 
 customer: I appreciate your help, thank you. 
 agent: You are most welcome. Have a safe flight.
Output:
book