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 help you? 
 customer: Mark Phillips here. Can you please help me in booking the ticket from LGA to AUS? 
 agent: May I know your trip dates? 
 customer: My trip dates are 03/21 and 03/23. 
 agent: There is a direct flight with flight number 1018, can I proceed? 
 customer: Please search for a flight with 1 halt. 
 agent: I am sorry to inform you that there is no flight available with 1 connection. 
 customer: That's ok, thank you for giving the information. 
 agent: Thank you for contacting us.
Output:
no_flight