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, Jerry Young here. 
 agent: Hello, how can I serve you? 
 customer: I want to alter my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please take your some time for helping me? 
 agent: Sure. Please wait a while. 
 customer: Ok. 
 agent: Sorry, there is no reservation under your name. 
 customer: Ok, thank you for the information. 
 agent: Thank you for reaching us.
Output:
no_reservation