299879
The network was extended to transport wood from the forests and by the middle of the 20th century the railway had a total length of 131,97 km , the most extensive forestry railway network in Czechoslovakia .
 Czechoslovakia
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Czechoslovakia