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 help you today? 
 customer: Helen Gonzalez here. Reserve a flight ticket for me that is from HOU to BOS. For my business trip. 
 agent: Sure, may I know your respective dates of journey please? 
 customer: My price limit is less than 500. My travelling dates for journey are 02/10 to 02/12. 
 agent: Ok, wait for a moment please. 
 customer: Sure. 
 agent: There is a direct flight of fare 100 and the airline is naming as Southwest, are you ok with this booking? 
 customer: You can book it. 
 agent: Ok, your booking is done with the flight number 1004. 
 customer: Thank you. 
 agent: You are welcome, have a nice day.
Student:
book