I've bought iPhone 5s SPRINT. I'm living in Russia, how can I unlock it, we have not such operator??

ONLY Sprint can unlock it.

Contact them and see if you qualify for this service.

For what reason did you purchase a device locked to a carrier in another country?

If the purchase was done in the last 30 days, RETURN the device and either purchase an unlocked device or one intended for use in your country.

FYI, warranty and support for that Sprint iPhone is only valid in the US.