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. 
 agent: Hello, how may I serve you? 
 customer: Can you help me to change my recent reservation because my trip dates are got postponed, can you help me? 
 agent: Sure, I am here to help you. 
 customer: Thank you. 
 agent: Please help me with your good name. 
 customer: I am Kimberly Collins. 
 agent: Sorry, there is no active reservation on your name. 
 customer: That's ok, thank you for checking. 
 agent: Thank you for opting us.
A:
no_reservation