Which continent is XXX on?
Russia
Following the Russian Revolution, the Russian Soviet Federative Socialist Republic became the largest and leading constituent of the Soviet Union abbreviated to USSR, the world's first constitutionally socialist state and a recognized world superpower, and a rival to the United States which played a decisive role in the Allied victory in World War II. The Soviet era saw some of the most significant technological achievements of the 20th century, including the world's first human-made satellite, and the first man in space.