How many vassal countries (J-joining countries) were there in the former Soviet Union?

According to the Constitution, the Soviet Union is a federal country, consisting of 15 Soviet socialist republics with equal rights (joining Soviet republics) according to the principle of voluntary alliance, but its government power is highly centralized, and it pursues the world's first complete socialist system and planned economy policy. Joining each other * * * The independence time of the Republic of China is as follows: Lithuania:1990 March1Georgia:1991April 9 Estonia:199/August 20. 23rd Ukraine: 1991August 24th Belarus:1991August 25th Moldova:1991August 27th Azerbaijan:199/kloc. Kloc-0/August 3 1 Day Tajikistan:1910 On February 25th, it was announced that the country name was changed from "Russian Soviet Federalist Socialist Republic" to "Russian Federation" (1990).