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1.
Russia
Kazakhstan - 7644km, China - 4179km, Mongolia - 3452km, Ukraine - 1944km.
2.
Germany
Austria - 801km, Czechia - 704km, Poland - 447km, France - 418km.
3.
Democratic Republic of the Congo (DRC)
Angola - 2646km, Zambia - 2332km, Republic of the Congo - 1775km, Uganda - 877km.
4.
Italy
Switzerland - 698km, France - 476km, Austria - 404km, Slovenia - 218km.
5.
Iraq
Iran - 1599km, Saudi Arabia - 811km, Syria - 599km, Turkey - 367km.
6.
China
Mongolia - 4630km, Russia - 4179km, India - 2659km, North Korea - 1352km.
7.
Sudan
South Sudan - 2158km, Chad - 1403km, Egypt - 1276km, Ethiopia - 744km.
8.
Brazil
Bolivia - 3403km, Peru - 2659km, Venezuela - 2137km, Argentina - 1263km.