Given the task definition and input, reply with output. 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

customer: Hello. 
 agent: Hello. 
 customer: Michael Miller here. 
 agent: How can I assist you? 
 customer: For my brother's marriage anniversary party, I want to go DFW from LAS. So, can you please book my ticket? 
 agent: Sure, please share your travel dates. 
 customer: My travelling dates are from 08/02 to 08/04. 
 agent: Please hold on for a moment, I will be back with the flight details. 
 customer: Sure. 
 agent: The flight 1026 of UA airlines is available on your requested dates with a price of 200. Shall I proceed? 
 customer: That's perfect. Please go ahead. 
 agent: Miller, your ticket is booked successfully. 
 customer: Thank you. 
 agent: You are welcome.
book