Detailed 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
Problem:customer: Hello. I am Scott Thomas. 
 agent: Hello, how can I help? 
 customer: I would like to attend Global Environmental Conference in Benaroya hall, which is at Washington. Can you book me a ticket from DEN to DCA? 
 agent: Sure, please help me with your travelling dates. 
 customer: I would start on 03/22 and return on 03/24. 
 agent: Do you have any specific preferences? 
 customer: I need a flight within price 5000. 
 agent: Please wait for a while. 
 customer: Sure. 
 agent: We have a connecting flight from Spirit airline, number 1024 and the price is 100. Shall I proceed? 
 customer: Yes, please go ahead. 
 agent: Your economy class seat is reserved. 
 customer: Thanks for your support. 
 agent: Thank you for choosing us.
Solution:
book