You will be given a definition of a task first, then some input of the task.
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: Hi, Margaret Evans is my name. 
 agent: Hello, how may I help you? 
 customer: I am willing to book a flight on Oct 25th to reach Philadelphia, so please help me in booking a flight with a halt. 
 agent: Sure, may I know your source and destination airport codes? 
 customer: Sure, my airport codes are HOU - PHL. 
 agent: Ok, when you will return from PHL? 
 customer: I have planned to return on 27th of Oct. 
 agent: Please wait a moment to check flight availability. 
 customer: Sure. 
 agent: We found a flight from Spirit airline with 1 connection and the fare is 100 with an economy class.Shall I proceed? 
 customer: Ok, please confirm my booking. 
 agent: Your ticket is booked with 1008 flight number. 
 customer: Thank you. 
 agent: Thank you for reaching us.
Output:
book