The document discusses the Russian alphabet. It notes that the Russian alphabet consists of 33 letters, including 10 vowels and 21 consonants. It traces the origins of the Cyrillic alphabet to the 9th century work of the Byzantine brothers Cyril and Methodius to create a writing system for Slavic languages. It was derived from their earlier Glagolitic alphabet. The Cyrillic alphabet became established as the written language of Russia in the 10th century and remains the basis of the modern Russian alphabet, with some reforms in the early 20th century.