Russian instrumental case for conjunction

Russian declension of nouns involves 6 cases: nominative, genitive, dative, accusative, instrumental, prepositional, in two numbers singular and plural (some Russian nouns are always plural or always singular), and absolutely obeying 3 grammatical genders: masculine, feminine, and neuter. Russian nouns are either animate or inanimate. Russian adjectives, pronouns and numerals decline too; they agree with nouns in gender, number and case.