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: Hello, I am Amy Johnson. 
 agent: Hello, how can I aid you? 
 customer: I want to book a flight ticket from LGA to HOU to meet my friend, can you please help me to book a flight with single connection? 
 agent: Help me with your travel dates? 
 customer: My trip dates are 01/13 to 01/15. 
 agent: Ok, please wait. 
 customer: Ok. 
 agent:  Sorry, no connecting flights are available on your journey dates. 
 customer: Ok, no worries at all. Thanks for your service. 
 agent:  Thank you for opting us.
Output:
no_flight