Given the task definition and input, reply with output. In this task, you are given dialogue, and you have to find the most critical location in the given conversation.

Hi there! Can you help me learn about Chicago? 
 I sure can, Chicago is the largest city in the U.S. state of Illinois, and the county seat of Cook County. It is the third largest city in the United States, although it used to the the second largest. 
 I didn't know it used to be the second largest. Can you tell me some information about the infrastructrue 
 In recent years of the state of Illinois has been leaning towards building an entirely new airport in the Illinois suburbs of Chicago. 
 Probably a good idea. Anything else they're building or have built recently? 
 The first skyscraper in the world, the Home Insurance Building, was built in Chicago. 
 Oh cool. I would've guessed it would've been built in NY. What other interesting things can you tell me about the infrastructure? 
 In addition, the Chicago medical school and Loyola University Chicago's stritch school of medicine are located in the suburbs of North Chicago and Maywood. 
 Good to know thanks! Do you know if the economy is strong there? 
 the city has also been rated as having the most balanced economy in the United States, due to its high level of diversification. 
 What are some other drivers of there economy? 
 The city and its surrounding metroplitan area contain the third- largest labor pool in the United States with about 4.63 million workers. 
 Thank you so much for this information! IT's been very helpful 
 No problem!

Chicago