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, myself Helen Gonzalez. 
 agent: Hello. How may I help you out? 
 customer: I am planning to book a flight ticket to LAS from LGA, can you please help me out? 
 agent: Sure, I will help you in booking the ticket. May I know your travelling dates please? 
 customer: Sure, my planned travelling dates are Feb 10 and Feb 12. 
 agent: There is a flight with connection 1 and price 400, can I proceed? 
 customer: Ok, please confirm my reservation. 
 agent: Ok, your ticket has been booked with flight number 1026. 
 customer: Thank you for the help. 
 agent: Thank you for reaching us.
book