Complex sentence: The International Inferno Race, comprising cross-country, giant slalom and downhill races, is the longest (15.8 km, 9.8 mi) and largest amateur ski race in the world with a limit of 1800 participants.
Split into simpler sentences: The International Inferno Race, comprising cross-country, giant slalom and downhill races, is the longest (15.8 km, 9.8 mi) and largest amateur ski race in the world. The Inferno Race--the largest amateur ski race in the world with 1800 participants.