Instructions: 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: I am Pamela Lewis. 
 agent: How may I aid you? 
 customer: Can you please help me to change my existing reservation as my plan to attend a film festival got postponed? 
 agent: Sure, I am ready to help you. 
 customer: Thank you. 
 agent: Sorry, there are no reservation found on your name. 
 customer: Ok, no problem. Thank you for the information. 
 agent: Thank you for choosing us.
Output:
no_reservation