367018
On February 14 , 1923 Detskoselsky and Petergofsky Uyezds were abolished and merged into Gatchinsky Uyezd , with the administrative center located in Gatchina .
 Gatchina
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Gatchina