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: Hi,. 
 agent: Hello, how may I serve you? 
 customer: Please change my existing reservation owing to an emergency. 
 agent: Sure, let me know your name to check the list and revert you. 
 customer: I am Ruth Edwards. 
 agent: Ok, please wait. 
 customer: Sure. 
 agent: We could not find any reservation by the name you gave. 
 customer: Thank you. 
 agent: Thank you for approaching us.
A:
no_reservation