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. 
 customer: I am Jeffrey Williams. 
 agent: How may I abet you today? 
 customer: I want to change my existing reservation as my tournament got rescheduled. Please help me. 
 agent: Sure, wait a moment I will check whether the reservation available or not. 
 customer: Ok. 
 agent: Thanks for waiting, we did not found any reservation by this name. 
 customer: No issues, thank you. 
 agent: Thanks for reaching us.
Student:
no_reservation