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: Hi. 
 agent: Hello. How may I assist you? 
 customer: Owing to an emergency I had to request for this change reservation. 
 agent: Sure, I will help you. May I know your name please? 
 customer: I am Nancy Johnson. 
 agent: Please wait a moment. 
 customer: Ok. 
 agent: Sorry Nancy Johnson, there is no reservation on your name. 
 customer: Thanks. 
 agent: Thank you.
Output:
no_reservation