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 assist you today? 
 customer: I want to travel from OAK to SEA. Can you help me to book a flight ticket? 
 agent: Sure, may I know your travelling dates? 
 customer: I want to fly in the flight on Sept 29 and Oct 01. 
 agent: Do you need any specification? 
 customer: I want to travel in a connecting flight. 
 agent: Please wait a moment. 
 customer: Ok, take your time. 
 agent: There is a flight with one connection and the price is 200 in Southwest Airlines, can I proceed with the reservation? 
 customer: Proceed to booking. 
 agent: Your ticket has been reserved with the flight number 1026. 
 customer: Thank you for your help. 
 agent: May I know your name? 
 customer: Janet Clark. 
 agent: Thank you for reaching our service.
book