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. 
 agent: Hello. How can I help you? 
 customer: Myself Benjamin Edwards. I want to book a ticket from DEN to DTW. 
 agent: Can I know your travel dates? 
 customer: My trip dates are from 07/05 to 07/07. 
 agent: Ok. Sorry Edwards, there are no flights available on your request. 
 customer: Oik, thank you for your help. 
 agent: Welcome.
no_flight