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. 
 customer: Brenda Thomas here. 
 agent: How may I help you? 
 customer: Can you please help me in changing my recent reservation? As my planned trip has been postponed to some other dates. 
 agent: Sure, I am here to help you with that. Sorry to say that, there is no reservation found on your name in our database. 
 customer: Oh! That's ok, thank you for giving the information. 
 agent: Thank you for reaching us.
Output:
no_reservation