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, I am Kathleen Campbell. 
 agent: Hello, how can I help you today? 
 customer: I want to book a ticket from HOU to DFW to surprise my friend on her birthday. Can you please help me to book a ticket on 06/28? 
 agent: Sure, we are here to help you. May I know the return date of your journey? 
 customer: My return journey date is 06/30. 
 agent: May I know is there any connection limit? 
 customer: I need only one connection limit. 
 agent: Ok, please wait for a while. 
 customer: Ok. 
 agent: Thanks for waiting. Sorry for the inconvenience, we have a direct flight with AA airline. 
 customer: Ok, Do not proceed for booking. 
 agent: Ok. 
 customer: Thanks for your assistance. 
 agent: Thanks for choosing us.
Output:
no_flight