Children, wearing red neckerchiefs, a symbol of the Pioneer Organization, salute during a ceremony for the inauguration of 18 new members at a local school in the southern settlement of Kazminskoye in Stavropol region, Russia, November 19, 2015. Early pro-communist youth movements, which appeared in Russia after the 1917 Bolshevik revolution, were reformed into the Pioneer Organization of the Soviet Union. While the organization lost its dominance among students in post-Soviet Russia, some educational institutions and families still carry on this tradition. (Photo by Eduard Korniyenko/Reuters)

Onati Basque dancers go airborne as they perform Basque traditional dances while making their way to the front of Saint Mark's Catholic Church, Saturday, August 1, 2015, in Boise, Idaho. The annual Mass, conducted in English and Basque, was held at the church for the first time. (Photo by Kyle Green/Idaho Statesman via AP Photo)

Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)

A chimpanzee relaxes in the shade at the Safari Park as the popular attraction prepares for the upcoming Jewish festival of Pesach (Passover) on April 14, 2008 in Ramat Gan near Tel Aviv, Israel. (Photo by David Silverman/Getty Images)

Tibetan men get ready to perform a traditional dance during a special prayer ceremony on the third day of the Tibetan New Year celebrations in Kathmandu, Nepal, Wednesday, March 1, 2017. Tibetans follow this ritual called “sangtsol” to ask for good luck in the new year. (Photo by Niranjan Shrestha/AP Photo)

A woman smokes marijuana during the annual 4/20 marijuana rally on Parliament Hill in Ottawa, Ontario, Canada, April 20, 2017. (Photo by Chris Wattie/Reuters)

An Indian Runner duck searches for food on a snow-covered meadow in Aitrang, southern Germany, Wednesday. April 19, 2017. (Photo by Karl-Josef Hildenbrand/DPA via AP Photo)

A woman attempts to cover a tear gas canister fired by police at a crowd in Srinagar protesting against the recent killings in Kashmir, August 17, 2016. (Photo by Cathal McNaughton/Reuters)