Sergey Ustiugov of Russia skis during the men's 15 km free style race at the cross country World Cup in Davos, Switzerland, Sunday, Dec. 10, 2017. (Gian Ehrenzeller/Keystone via AP)

Sergey Ustiugov of Russia skis during the men's 15 km free style race at the cross country World Cup in Davos, Switzerland, Sunday, Dec. 10, 2017. (Gian Ehrenzeller/Keystone via AP)