Teacher: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
Teacher: Now, understand the problem? Solve this instance: customer: Hi. 
 agent: Hello, how can I best assist you now? 
 customer: Can you please avail me a flight ticket from BOS to PHL? 
 agent: Kindly mention your travelling dates? 
 customer: My trip dates are Jan 5 - Jan 7. 
 agent: Do you need any break in between journey? 
 customer: I need a single connection. 
 agent: May I know your name? 
 customer: Lisa Smith here. 
 agent: Is there any another specifications on your trip? 
 customer: No. 
 agent: Thanks for sharing your details, we are unable to provide flight in between your journey routes. 
 customer: No issues, thank you. 
 agent: Thanks for reaching us.
Student:
no_flight