Teacher: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
Teacher: Now, understand the problem? Solve this instance: customer: Hi. 
 agent: Hello, how may I support you? 
 customer: I have planned to book a plane ticket from PHL to SEA, can you assist me in booking my ticket? 
 agent: Sure, when are you planning to travel? 
 customer: My preferred dates are Oct 18th and Oct 20th. 
 agent: What is your maximum connection limit? 
 customer: I need single connection between my trip. 
 agent: Do you have any preferences? 
 customer: No. 
 agent: Please forward your name. 
 customer: Matthew Walker. 
 agent: Ok, please wait. 
 customer: Sure. 
 agent: Thanks for waiting, there are no flights going on your way at this moment. 
 customer: No problem, thank you for searching. 
 agent: Thank you for reaching us.
Student:
no_flight