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: Hi. 
 agent: Hello, how may I help you? 
 customer: I want to change an existing reservation due to an emergency, can you please help me? 
 agent: Sure, may I know your name? 
 customer: Sure, my name is Virginia Williams here. 
 agent: Please wait a moment. 
 customer: Sure, I will wait. 
 agent: Sorry, there are no active reservations on your name to change. 
 customer: Ok, not an issue.Thank you for your information. 
 agent: Thank you for reaching our service.
A:
no_reservation