Given the task definition and input, reply with output. 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

customer: Hi. I am Janet Williams. 
 agent: Hello Janet, how may I help you today? 
 customer: Can you help me in booking from OAK to PHL, as there is a business meeting to attend at Oakland? 
 agent: Sure Janet, could you please share me with your dates of travel? 
 customer: My trip dates are 08/21 to 08/23. 
 agent: Please wait for a mean while. 
 customer: Ok. 
 agent: There is a flight with the connecting flight of fare 100 and the airline is Frontier, are you ok with this booking? 
 customer: You can reserve it. 
 agent: Ok, your ticket has been reserved with the flight number 1024. 
 customer: Thank you. 
 agent: You are welcome, have a safe journey.
book