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. May I know you name? 
 customer: I am Debora Nelson, I am planning a trip for my cousin's engagement from LAS -EWR can you find a ticket for me? 
 agent: It's good to hear, could you provide your journey dates? 
 customer: Sure, my travelling dates are 03/20 to 03/22. 
 agent: Sorry Nelson, we could not found any flight as per your requested information. 
 customer: OK, thank you. 
 agent: OK, thank you for reaching us. Have a great day Nelson.
Output:
no_flight