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: Hello. 
 agent: Hello. 
 customer: I am Patricia Lee. 
 agent: Patricia Lee, how may I render you? 
 customer: I have a plan to attend the nature festival in Seattle, can you please book a flight ticket from PHL to SEA? 
 agent: Sure, please provide your itinerary dates. 
 customer: My planned journey dates are Oct 15th and Oct 17th. 
 agent: Do you have any specifications? 
 customer: I need a lay by. 
 agent: Sorry, no flight is providing service on your planned dates. 
 customer: Ok, not an issue. Thank you. 
 agent: Thank you for reaching us.
Student:
no_flight