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 can I help you? 
 customer: Could you assist me in cancel my recent reservation? 
 agent: Sure, could you please tell me your name? 
 customer: I'm Carolyn Roberts. 
 agent: OK. Give me a moment Carolyn. 
 customer: OK. 
 agent: Sorry to inform you that there is no reservation found on your name. 
 customer: OK. Thank you for information. 
 agent: Thank you for reaching us.
no_reservation