Complex sentence: He represented the USSR, and won three Olympic gold medals at the 1980 Summer Olympics in Moscow in the K-1 500 m, K-2 500 m, and K-2 1000 m events.
Split into simpler sentences: He represented the USSR, and won three Olympic gold medals at the same Olympic Games. He achieved this at 1980 Summer Olympics in Moscow, winning golds in the K-1 500 m, K-2 500 m, and K-2 1000 m events.