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, how can I aid you? 
 customer: I am Charles Miller. I am planning to go for Yosemite Adventure with my friends at Detroit, can you please book a ticket under the price 5000? 
 agent: Sure, can you share your trip dates? 
 customer: I want to travel on 04/26, and need to catch return flight on 04/28. 
 agent: Do you need any halt in between your journey? 
 customer: I need a halt. 
 agent: May I know your journey airport codes? 
 customer:  I need to leave from my nearest airport HOU to reach DTW. 
 agent: Give me a minute. 
 customer: Sure. 
 agent: There is a connecting flight with number 1013 in airline Southwest, the fare is 100. Can I book it? 
 customer: Proceed with the booking. 
 agent: Your ticket is reserved. 
 customer: Thanks for the help. 
 agent: Thank you for opting us.
book