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. 
 agent: Hello, how can I help you? 
 customer: On 10/19 my birthday so, I want to go to Baitul Islam Mosque to take namaz. Can you please book a ticket from New York, LGA? 
 agent: Sure, please share me your airport codes? 
 customer: My destination code is Detroit, DTW. 
 agent: Kindly mention me your return date? 
 customer: Sure, I have to return on 10/21. 
 agent: Do you have any specifications? 
 customer: 1000 is my fare limit and I need a halt in between. 
 agent: OK, please wait a minute. 
 customer: Sure. 
 agent: We found 1013 UA airline with single connection and price of 200. Shall I proceed with booking? 
 customer: Please proceed. 
 agent: To proceed with booking, we need your name? 
 customer: Ok, my name is Melissa Nelson. 
 agent: Your ticket has been booked. 
 customer: Thanks a lot for making a reservation for me. 
 agent: Thank you for reaching us.
book