 Complete the following phrase:  The 51st Rifle Division was an infantry division of the Soviet Army, formed twice. Its first formation was formed during the Russian Civil War and fought in the Perekop-Chongar Offensive in 1920. It also fought in the Soviet invasion of Poland, Winter War and World War II. During World War II, it fought in the Battle of Rostov, Barvinkove-Losowaja Operation and 