Original sentence: Formally known as the Annexation of Crimea by the Russian Federation, also called by some the accession of the Republic of Crimea to the Russian Federation is a disputed diplomatic process that began after the Autonomous Republic of Crimea and the city of Sevastopol unilaterally declared their independence from Ukraine
Edited sentence: The accession of the Republic of Crimea to the Russian Federation is a disputed diplomatic process that began after the Autonomous Republic of Crimea and the city of Sevastopol unilaterally declared their independence from Ukraine