Complex sentence: Viktor Stepanovich Chernomyrdin (,; 9 April 19383 November 2010) was the founder and the first chairman of the Gazprom energy company and the longest serving Prime Minister of Russia (1992--1998).
Split into simpler sentences: Viktor Stepanovich Chernomyrdin (,; 9 April 19383 November 2010) was a Russian politician. He was the first chairman of the Gazprom energy company and the longest-serving Prime Minister of Russia (1992--1998).