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 assist you today? 
 customer: I am looking for a flight on Sept 23 to visit my home. Can you book a flight for me? 
 agent: Sure, I will help you. Please help me with your name. 
 customer: My name is Carolyn Williams. 
 agent: Please help me with your depart and arrival airport codes. 
 customer: My source point is MSP and my destination is IAD. 
 agent: Please help me with your return date of journey. 
 customer: I will return on Sept 25. 
 agent: Do you need a break in between your journey? 
 customer: Yes, I need a break. 
 agent: Do you have any other preferences in your journey? 
 customer: No. 
 agent: Carolyn Williams, I am really sorry to inform you that there are no flights available for your journey. 
 customer: Ok, thank you for the information. 
 agent: Thank you for reaching us. Have a great time.
Output:
no_flight