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 can I help you? 
 customer: I am planning to attend a Tennis competition in AUS from EWR. Can you find a ticket for me? 
 agent: Sure, I will check for the available flights. Can you please share your trip dates? 
 customer: Sure, my dates are 05/07 to 05/10. 
 agent: Can you please tell me your good name for further process? 
 customer: Yes, I am Edward Wright. Sorry, I changed my return date that is 05/09. 
 agent: Ok, please wait a minute. 
 customer: Sure. 
 agent: Sorry to inform you Wright, due to some climate changes there are no flights available in the dates you planned. 
 customer: OK, thank you for your information. 
 agent: You are welcome. Thank you for contacting us.
Output:
no_flight