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: Consider Input: customer: Hello. 
 agent: Hello. How can I serve you? 
 customer: I am Raymond Allen. I want to change an existing reservation, due to my health issues. Could you help me in changing the reservation? 
 agent: Sure, I can help you. Please wait a while. 
 customer: Sure. 
 agent: Thanks for being waiting. We didn't found any reservation by this name. 
 customer: Not an issue. Thank you. 
 agent: Thank you.

Output: no_reservation


Input: Consider Input: customer: Hi. 
 agent: Hello, how may I lend a hand to? 
 customer: I need to change my existing reservation as my trip got postponed, Can you please help me with that? 
 agent: Sure, I am here to help you for this. Could you please mention your name? 
 customer: Kevin Williams here. 
 agent: Please wait for a while, let me check your reservation status in our records. 
 customer: Sure. 
 agent: Sorry for inconvenience, no reservation is found with your criteria. 
 customer: Ok, no problem. Thanks for your information. 
 agent: Thank you very much for contacting our agency.

Output: no_reservation


Input: Consider Input: customer: Hello. 
 agent: Hello, how can I best support you today? 
 customer: I am Samuel Green. I want to change my existing reservation due to the change of my trip dates. Can you help me? 
 agent: We are here to help you. 
 customer: Thank you. 
 agent: Just give me a moment please. 
 customer: Sure. 
 agent: Sorry to say that there is no reservation found on your name. 
 customer: No problem. Thank you for your response. 
 agent: Thanks for connecting us, have a nice day.
Output: no_reservation