Slavs
Slavs can be further grouped by religion. Orthodox Christianity is practiced by the majority of Slavs. The Orthodox Slavs include the Belarusians, Bulgarians, Macedonians, Montenegrins, Russians, Serbs, and Ukrainians and are defined by Orthodox customs and Cyrillic script as well as their cultural connection to the Byzantine Empire (Serbs also use Latin script on equal terms). Their second most common religion is Roman Catholicism. The Catholic Slavs include Croats, Czechs, Kashubs, Moravians, Poles, Silesians, Slovaks, Slovenes, and Sorbs and are defined by their Latinate influence and heritage and connection to Western Europe. There are also substantial Protestant and Lutheran minorities especially amongst the West Slavs, such as the historical Bohemian (Czech) Hussites.
Ukrainian Soviet Socialist Republic
Geographically, the Ukrainian SSR was situated in Eastern Europe to the north of the Black Sea, bordered by the Soviet republics of Moldavia, Byelorussia, and the Russian SFSR. The Ukrainian SSR's border with Czechoslovakia formed the Soviet Union's western-most border point. According to the Soviet Census of 1989 the republic had a population of 51,706,746 inhabitants, which fell sharply after the breakup of the Soviet Union. On January 1, 2018, according to the State Statistics Committee of Ukraine the population of the country was 42,216,766 permanent residents.