 Complete the following phrase:  Shalamov joined a Trotskyist-leaning group and on February 19, 1929, was arrested and sent to Butyrskaya prison for solitary confinement. He was later sentenced to three years of correctional labor in the town of Vizhaikha, convicted of distributing the Letters to the Party Congress known as Lenins Testament, which were critical of Joseph Stalin, and of participating in a demonstration marking the tenth anniversary of the 