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
Input: customer: Hello. 
 agent: Hello. How can I serve you? 
 customer: I am Raymond Allen. I want to change an existing reservation, due to my health issues. Could you help me in changing the reservation? 
 agent: Sure, I can help you. Please wait a while. 
 customer: Sure. 
 agent: Thanks for being waiting. We didn't found any reservation by this name. 
 customer: Not an issue. Thank you. 
 agent: Thank you.
Output:
no_reservation