5786
Its source is confluence of the Stupčanica and the Bioštica rivers at the western outskirts of town of Olovo .
 Stupčanica, Bioštica, Olovo
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Stupčanica, Bioštica, Olovo