Complex sentence: The Prix Chaudenay is a Group 2 flat horse race in France for three-year-old thoroughbreds run over a distance of 3,000 metres (approximately 1 mile 7 furlongs) at Longchamp Racecourse on the weekend of the first Sunday in October.
Split into simpler sentences: The Prix Chaudenay is a Group 2 flat horse race in France for three-year-old thoroughbreds. It is run over a distance of 3,000 metres (approximately 1 mile 7 furlongs) at Longchamp Racecourse on the weekend of the first Sunday in October.