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. I am Donald Parker. 
 agent: Hello, how can I help you today? 
 customer: Due to sudden work, I need to change my reservation. Can you please help me with it? 
 agent: Sure, please wait for a moment. 
 customer: Ok. 
 agent: Sorry to say that, no reservation was found with your good name. 
 customer: Ok, not an issue. Thank you. 
 agent: Thank you for reaching us.
Output:
no_reservation