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, I am Shirley Williams. 
 agent: Hello, how may I aid you? 
 customer: I am planning to going for Navajo adventures at Washington, DC-IAD. So please help me in booking a flight ticket from San Francisco, SFO? 
 agent: Sure, can you please provide your travelling dates? 
 customer: My journey dates are from 05/10 to 05/12. 
 agent: Do you need any stopover in between your journey? 
 customer: Yes, I need a stopover in between journey. 
 agent: Thanks for the information, there is no flight available matching with your requirements. 
 customer: Ok, not a problem. 
 agent: Thanks for reaching us. 
 customer: Thanks for your information.
Output:
no_flight