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

Input: Consider Input: customer: Hello. 
 agent: Hello, how can I assist you? 
 customer: I need to cancel my ticket due to sudden change in my trip, can you aid me in cancellation process? 
 agent: Sure, I am here to aid you. May I know your name please? 
 customer: Amanda wright. 
 agent: Ok, please wait a minute. 
 customer: Ok. 
 agent: Thank you for waiting, sorry no reservation found on your name. 
 customer: No problem, thank you for searching. 
 agent: Thank you for reaching us, have a nice day.

Output: no_reservation


Input: Consider Input: customer: Hi, Joshua Green here. 
 agent: Hello, how can I help you today? 
 customer: I am planning to book a flight in the afternoon time on 6th of Sept to reach Seattle, so please help me in booking a normal-cost flight. 
 agent: Sure, may I know your source and destination airport codes? 
 customer: Sure, my source and destination airport codes are DCA - SEA. 
 agent: May I know your return date? 
 customer: Sure, I intend to return on 8th of Sept. 
 agent: Do you need halt in between your journey? 
 customer: Yes, I prefer it. 
 agent: Ok, please wait for a moment. 
 customer: Sure. 
 agent: Sorry, there are no flights found with your given dates. 
 customer: No worries, thank you for informing me. 
 agent: Thank you for opting us.

Output: no_flight


Input: Consider Input: customer: Hi, I am Alexander Anderson. 
 agent: Hello, How exactly can I serve you now? 
 customer: I am excited to go Haunted Pub tour at Washington,DC - DCA. Can you help me with booking a connecting flight? 
 agent: Ok, please share your travelling dates? 
 customer: I will fly on 03/20 and 03/22. 
 agent: May I know your source code? 
 customer: I want to board from Detroit, MI - DTW. 
 agent: Ok, please wait. 
 customer: Sure. 
 agent: We found a 1007 Delta airline, with fare 100 for your journey. 
 customer: Please proceed. 
 agent: Your booking is done. 
 customer: Thanks for your assistance. 
 agent: Thanks for approaching us.
Output: book