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, I am Richard Clark.
agent: Hello, how best can I serve you?
customer: I am going to enjoy my holiday trip in the Redwood Regional Park with my colleagues, which is at Los Angeles. Can you help me in booking a flight ticket from DCA to LAX?
agent: Sure, I will help you. Can you please provide your travel dates?
customer: I would start on 12/17 and return on 12/19.
agent: Do you have any specifications?
customer: Yes, I need a flag stop.
agent: We found an airline AA with flight number 1012 having a fare of 100 with halt.
customer: Ok, please proceed.
agent: Shall I proceed with booking? Ok. Your booking has been processed.
customer: Thanks for your support.
agent: Thank you for reaching us.
book