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: Hi. 
 agent: Hello, how can I assist you today? 
 customer: I need to change my reservation as my plan to go for trekking got postponed. Can you help me? 
 agent: Sure, let me know your name. 
 customer: I am Ryan Mitchell. 
 agent: Ok, please wait for a while. 
 customer: Sure. 
 agent: Sorry to say that, no reservation was found on your name. 
 customer: That's Ok, thanks for your assistance. 
 agent: Thank you for choosing us.
Output:
no_reservation