Instructions: 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
Input: customer: Hello. 
 agent: Hello, how may I serve you today? 
 customer: I am looking for a flight from SEA to BOS, can you help me in booking? 
 agent: Sure, can I have your travel dates please? 
 customer: Sure, my planned travel dates are Apr 11 and Apr 13. 
 agent: May I know your good name? 
 customer: Myself Cynthia Miller. 
 agent: Please share your connection limit. 
 customer: Please look for a connecting flight as I need a break in between the journey. 
 agent: Do you have any other requirements to be met? 
 customer: No, thank you. 
 agent: Sorry, there is no flight on your required route. 
 customer: That's ok, no problem. Thank you for the information. 
 agent: Thank you for opting us.
Output:
no_flight