15739
As the two experts are constantly discussing , saying that the four northern islands issue is a dead knot in Japanese - Russian relations , yet this dead knot , it seems that currently both sides have this idea , they want to untie this dead knot .
 two, four, Japanese - Russian
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: date, organization, person, geographical social political, national religious political, facility, cardinal, location, work of art, law, event, product, ordinal, percent, time, quantity, money, language 
Text: {0} 
Answer:
 two, four, Japanese - Russian