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, how may I guide you today? 
 customer: Please book me a flight ticket from DTW to HOU to meet my family members. 
 agent: Sure, please let me know your good name. 
 customer: Myself Jacob Hill. 
 agent: When do you want to travel? 
 customer: I have planned to travel on June 07th and return on June 09th. 
 agent: Is there any connection limit? 
 customer: I prefer connecting flight. 
 agent: Do you have any other specifications? 
 customer: No, thank's for asking me. 
 agent: There is an economy class ticket in Hawaiian airlines with fare 100 and it is a connecting flight. Can I book your ticket? 
 customer: Ok, please book this ticket. 
 agent: Your ticket has been reserved with flight number 1002. 
 customer: Thank you so much. 
 agent: Thank you for opting us.
book