Given the task definition and input, reply with output. 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. 
 customer: I am Sarah Wright. 
 agent:  Sarah Wright. How may I help you? 
 customer: I would like to book a flight ticket from PHX to attend a robotic workshop at LGA, can you help me to book an economy class ticket? 
 agent: Sure, can you provide me the travel dates? 
 customer: My travelling dates are 11/08 and 11/10. 
 agent: Give me a moment. 
 customer: Ok. 
 agent: Do you have any preferences? 
 customer: I need a connecting flight. 
 agent: I regret to inform that, there are no flights on your desired dates. 
 customer: That's ok, thank you for the response. 
 agent: Thank you for approaching us.
no_flight