Definition: 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. Sandra Jones here. 
 agent: Hello, how can I serve you today? 
 customer: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that? 
 agent: Sure, I will help you. Please wait for a while. 
 customer: Ok, I will wait. 
 agent: Thanks for waiting, there is no active reservation found on your name. 
 customer: Anyway, thanks for the information. 
 agent: Thank you for availing us, hope to serve you again.
Output:
no_reservation