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. How may I guide you today? 
 customer: I am Ruth Gonzalez here. I want to change my previous  travelling dates. Can you please help me out in changing my existing  reservation? 
 agent: Sure, I will help you with that. 
 customer: Thank you for considering my request. 
 agent: Please wait for a minute. 
 customer: Sure, I will wait for your response. 
 agent: I am sorry to say that there is no reservation found under your name. 
 customer: Not a problem, anyway, thank you for the information. 
 agent: Thank you for reaching us, have a great day.
A:
no_reservation