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? 
 customer: Can you help me in booking from MSP to IAD, as there is a team outing? 
 agent: Sure, I am gleeful to help you. Could you please provide your travelling dates to search for the flight? 
 customer: My trip dates are Jul 30 to Aug 1. 
 agent: Do you have any connection limit? 
 customer: I need a connecting flight which return in evening. 
 agent: May I know your name? 
 customer: I am David Lopez. 
 agent: There is a connecting flight 1003 of Frontier airlines, can I proceed? 
 customer: You can reserve it. 
 agent: Sorry to say, there is no flight at evening time on your return journey. 
 customer: No issue, thank you. 
 agent: Thank you for reaching us.
Output:
no_flight