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 out? 
 customer: I would like to change my existing reservation, which is done recently. Can you please help me out? 
 agent: Sure, I will help you in changing the ticket. May I know your name please? 
 customer: Thank you for considering my request. Myself Robert Williams. 
 agent: Sorry, there are no reservations found in our database. 
 customer: That's ok, no problem. 
 agent: Thank you for reaching us. 
 customer: Thank you for the information.
no_reservation