81611
Some of the world 's largest swamps are found along major rivers such as the Amazon , the Mississippi , and the Congo .
 Amazon, Mississippi, Congo
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:
 Amazon, Mississippi, Congo