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: Hi. 
 agent: Hello, how may I help you today? 
 customer: From 11/20 to 11/22, I have an important meeting with my company share holders. So, please help me in booking flight ticket. 
 agent: Sure, I am here to help you. 
 customer: Thank you. 
 agent: Could you please provide your source and destination points? 
 customer: Sure, My source : Boston, MA - BOS and My destination : Chicago, IL - ORD. 
 agent: Do you need a halt in between your journey? 
 customer: obviously, I need a halt in between my journey. 
 agent: May I know your name please? 
 customer: Sure, My name is Jack Hall. 
 agent: OK, please wait for a moment. 
 customer: Sure. 
 agent: Thanks for waiting, we found an UA airline with single connection and fare is 100. Shall I proceed? 
 customer: Everything perfect, you may please proceed. 
 agent: Your ticket has been booked with 1005 flight. 
 customer: Thank you. 
 agent: Thank you for reaching us, have a safe journey.
book