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. 
 agent: Hello. How may I guide you today? 
 customer: Can you aid me to change my reservation due to bad weather conditions? 
 agent: Sure, I will help you with that. 
 customer: Dennis Harris here. 
 agent: Please wait for a while, I will get back to you. 
 customer: Ok. 
 agent: I am sorry to say that there is no reservation found under your name. 
 customer: It's not a big deal. 
 agent: Thank you for reaching us, have a great day. 
 customer: Thank you.
Output:
no_reservation