Detailed 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
Q: customer: Hello, I am Shirley Martinez. 
 agent: Hello, how can I serve your today? 
 customer: I want to visit HOU from my hometown PHL, can you help me with single connection of flight? 
 agent: Sure, may I know your travelling dates? 
 customer: My depart is on 04/26 and return on 04/28. 
 agent: please mention your connections. 
 customer: I need a lay by in between journey. 
 agent: There is a Frontier 1002 with fare of 100 which matches your travelling dates. Shall I proceed with booking? 
 customer: OK, proceed with booking. 
 agent: Your booking has been confirmed on name of Shirley Martinez. 
 customer: Thank you for the help. 
 agent: Thank you for approaching us.
A:
book