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. 
 customer: Stephen Young here. 
 agent: What service that you are expecting from our agency? 
 customer: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that? 
 agent: Sure, I am glad to help you with that. 
 customer: Thanks. 
 agent: Please wait a moment to check your previous reservation status. 
 customer: Ok, I will wait. 
 agent: We regret to inform you that, when I have checked your reservation there is no reservation showing on your name in our database. 
 customer: Anyway, thanks for the information. 
 agent: Thank you for using our services, have a great day.
A:
no_reservation