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Viktor Yushchenko served as the fourth President of Ukraine from 2005 to 2010. He was the leader of the Our Ukraine political bloc and a leading figure in the Orange Revolution. Yushchenko was elected president in a controversial run-off election against Viktor Yanukovych in 2004. The election was marred by widespread fraud and voter intimidation, which led to the Orange Revolution protests and the eventual overturning of the election results.