You will be given a definition of a task first, then some input of the task.
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

customer: Hi. 
 agent: Hello, how may I help you today? 
 customer: Can you please help me with booking a flight ticket from DCA to DTW? 
 agent: Sure, let me know your travelling dates. 
 customer: My travel dates are Nov 20 and 22. 
 agent: Do you want connecting flight? 
 customer: I need a connecting flight. 
 agent: Do you have any other requirements? 
 customer: I would like to depart at morning. 
 agent: May I know your name please? 
 customer: My name is Sharon Campbell. 
 agent: Ok, please wait for a moment. 
 customer: Ok. 
 agent: Sorry, there are no flights found with your given details. 
 customer: Ok, no issues. Thank you. 
 agent: Thank you for opting us.
Output:
no_flight