Detailed Instructions: 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
Q: customer: Hello, I am Christine Carter. 
 agent: Hello, how may I help you at this moment? 
 customer: As my manager did not approve my leave, so I would like to cancel my ticket. 
 agent: Can I have a moment please? 
 customer: Sure, take your time. 
 agent: Sorry, no ticket is showing on your name. 
 customer: That's ok, may be my friend has cancelled it before. 
 agent: Yes, it may be. Thank you for approaching us. 
 customer: Welcome.
A:
no_reservation