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: Hi. 
 agent: Hello, how can I help you? 
 customer: Owing to an emergency, I want to cancel my reservation. Can you check whether there is any refund policy on my reserved ticket? 
 agent: Please wait a while, may I know your name please? 
 customer: Sure, my name is Charles Johnson. 
 agent: Sorry to say, there is no reservation on your name in our database. 
 customer: That's ok, thank you for checking. 
 agent: Thank you for opting us.
no_reservation