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. How can I help you? 
 customer: Can you help me to book a flight ticket from PHL to IAD? 
 agent: Sure. Let me know your travelling dates. 
 customer: My travel dates are Oct 03 and Oct 05. 
 agent: Can I know your name? 
 customer: My name is Sarah Taylor. 
 agent: Do you have any preference? 
 customer: I prefer connecting flight on this route. 
 agent: Found ticket with airline Southwest for price 100 having flight number 1000. 
 customer: Please proceed to book my flight ticket in this airlines. 
 agent: Ticket is booked. 
 customer: Thank you. 
 agent: Thank you.
Student:
book