You will be given a definition of a task first, then some input of the task.
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.

customer: Hi. 
 __ 
 customer: I want to book a ticket from DCA to ATL, can you help me? 
 agent: Sure, I am here to assist you. Can you please tell us your name? 
 customer: I am David Thompson. 
 agent: Thank you. May I know your travel dates? 
 customer: My travel dates are 10/27 and 10/29. 
 agent: Ok, please let me know your preferences. 
 customer: I want to travel in normal cost airline. 
 agent: Ok, please wait for sometime. 
 customer: I prefer a connecting flight. 
 agent: Sorry, there is no flight available on your given travel dates. 
 customer: No problem, thanks for checking. 
 agent: You are welcome and thank you for choosing us.
Output:
agent: Hello, how may I help you?