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, how may I aid you? 
 customer: Can you please help me for booking from DTW to MCO? 
 agent: Sure, please provide your itinerary dates. 
 customer: My travelling dates are on May 09 and 11. 
 agent: Which class do you prefer? 
 customer: I need an economy class. 
 agent: Do you prefer a direct flight? 
 customer: I need a connected flight. 
 agent: May I know your name? 
 customer: Catherine Roberts here. 
 agent: Please wait for a while. 
 customer: Sure. 
 agent: Sorry Catherine Roberts, no flights are available as per your requirements. 
 customer: Ok, thank you. 
 agent: Thank you for reaching us.
Output:
no_flight