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 help you? 
 customer: Can you please help me in booking the flight ticket from LGA to IAD? 
 agent: Do you have any requirements? 
 customer: I prefer to travel in normal cost airlines with direct flight. 
 agent: Can you please share your travelling dates? 
 customer: My travel dates are 11/09 and 11/11. 
 agent: May I know your name? 
 customer: My name is Charles Phillips. 
 agent: Sorry to say, no flight is available for you. 
 customer: Ok, thank you for the information. 
 agent: Thank you for reaching us.
no_flight