Definition: In this task, you're given a dialogue between a customer and a flight booking agent with a gap in the conversation. Your job is to find the answer of the previous dialogue. Avoid using irrelevant extra information while creating the answer. The answer should be relevant to the question before the blank. If you fill the blank with a question, it should have an answer from the agent in the given dialogue. Fill the gap marked with underline.
Input: customer: Hi, I am Amanda Phillips. 
 agent: Hello, how can I serve you? 
 __ 
 agent: Sure, give me sometime to check and revert to you. 
 customer: Ok. 
 agent: Thank you for waiting. Unfortunately we didn't found any reservation according to your name. 
 customer: Ok, not an issue. Thank you. 
 agent: Thank you for opting us.
Output:
customer: I want to do some changes in the existing reservation because my friends are not able to come on those dates, can you help me in changing an existing reservation?