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: Hello, is this ABC flight booking agency? 
 agent: Yes, how may I help you today? 
 customer: Actually, I want to travel Denver on 07/17 to participate in a sport event which is going to be held, can you find an airlines to travel? 
 agent: Can I know your airport codes please? 
 customer: My airport codes are from SFO to DEN. 
 agent: May I know your travel dates? 
 customer: I would like to be return on 07/19. 
 agent: There is a flight available with price 100 and flight number is 1018, would you like to proceed with the booking? 
 customer: Perfect, let's go a head and book it. 
 agent: Your ticket is confirmed. And may I know your name please? 
 customer: Thank you, you've made this process very easy for me. My name is Stephanie Lee. 
 agent: Thank you Lee for contacting us. 
 customer: Welcome.
book