Russian language uses Cyrillic in contrast to English which uses Latin letters.
This may lead to some confusion in particular in those case where the Russian characters exist in Latin letters as well though with different meaning. Eastern , Western Roman empire anyone . . .
Thus we have the following situation:
SSSR = Soyuz Sovetskikh Sotsialisticheskikh Respublik
CCCP = Союз Советских Социалистических Республик
USSR = Union of Soviet Socialist Republics
Quite a tongue twister even for the native speaker. Russian words tend to be long and a word like “Sotsialisticheskikh” is awfully difficult to get right. But with a bit of practice the dilligent student will succeed!