Sukhoi Su-30SM jet fighters of the Russkiye Vityazi (Russian Knights) aerobatic team perform during a demonstration flight in Krasnoyarsk, Russia October 6, 2018. (Photo by Ilya Naymushin/Reuters)

A cadet lies on the grass after collapsing during a promotion ceremony at a police school in Bogota December 7, 2012. (Photo by John Vizcaino/Reuters)

Cuban girls dressed as nurses and a lizard wait for their turn to dance during a visit by the Gay Men's Chorus of Washington in Havana July 13, 2015. The choir made its first appearance on July 12, 2015 in Cuba as part of a tour that will include a dozen concerts in the context of the restoration of relations between the island and the United States. (Photo by Enrique de la Osa/Reuters)

Blood drips down from the face of a Shi'ite Muslim boy after practicing a self-flagellation ritual during a religious procession of the Ashura mourning period on December 6, 2011 in New Delhi, India. (Photo by Daniel Berehulak/Getty Images)

Models smoke during a break at Sevilla de Boda (Seville Wedding) fashion show in the Andalusian capital of Seville November 27, 2015. (Photo by Marcelo del Pozo/Reuters)

People make their way on an algae-covered beach in Qingdao, Shandong province, China, July 19, 2015. (Photo by Reuters/Stringer)

Revellers pose during the 24th Street Parade dance music event in Zurich, August 29, 2015. (Photo by Arnd Wiegmann/Reuters)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)