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 may I aid you today? 
 customer: I am Angela Martinez, can you help me to book a flight with 1 connection? 
 agent: Sure, I will help you. Can I know your travelling dates? 
 customer: My travelling dates are 06/30 and 07/02. 
 agent: Ok, may I know your airport codes? 
 customer: My preferable airport codes are BOS and IAH. 
 agent: Sorry to say that, there are no flight available based on your traveling dates. 
 customer: Ok, no issues. Thank you for your help. 
 agent: Thank you for approaching us.
Student:
no_flight