63138
The largest grouping of people in the company was in Illinois , at Naperville-Lisle , in the Chicago area , which had the largest concentration of employees ( about 11,000 ) prior to 2001 .
 Illinois, Naperville-Lisle, Chicago
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Illinois, Naperville-Lisle, Chicago