Q: 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, do you need any help from us? 
 customer: Please help me in changing my existing reservation, as my trip got postponed. 
 agent: Sure, could I have your name please? 
 customer: My name is Linda Collins. 
 agent: Ok, please allow me a moment. 
 customer: Ok. 
 agent: Sorry, there is no reservation with your name in our portal to make changes further. 
 customer: That's ok, thank you for the response. 
 agent: You are welcome, have a great day.
A:
no_reservation