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. How can I assist you? 
 customer: I want to travel from HOU to AUS. Can you please help me for booking? 
 agent: Sure, I will help you. Your good name please? 
 customer: Sure, my name is James Carter. 
 agent: Could you please share your planned journey dates? 
 customer: My planned journey dates are 10 and 12 on the month of March. 
 agent: Let me know your connection limit. 
 customer: I need a connected flight. 
 agent: Which class would you prefer for your journey? 
 customer: I am fine with any class. 
 agent: Do you have any other preferences? 
 customer: My depart time is evening. 
 agent: Give me a minute, I will let you know the flight availability. 
 customer: Sure. 
 agent: Thank you for your time, there were no flights available that matches your requirements. 
 customer: Ok, thanks for your assistance. 
 agent: Thank you for approaching us.
Output:
no_flight