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: Hi. 
 agent: Hello, how can I aid you for the day? 
 customer: My exams got postponed to future dates, so I need to cancel my reservation. Can you please help me out? 
 agent: Sure, I will help you. 
 customer: Thank you. 
 agent: May I know on which name the ticket has been reserved? 
 customer: Reservation has been made on the name of Benjamin Jones. 
 agent: Please wait a moment. 
 customer: Ok. 
 agent: Sorry to inform you that there is no reservation found on with your name. 
 customer: Ok, no issues. 
 agent: Thank you for opting us. 
 customer: Thank you for your information.
no_reservation