A migrant smokes a cigarette as he waits among others to cross the Croatian border near the village of Berkasovo, Serbia October 19, 2015. Thousands of migrants clamoured to enter European Union member Croatia from Serbia on Monday after a night spent in the cold and mud of no-man's land, their passage west slowed by a Slovenian effort to impose limits on the flow to western Europe. (Photo by Marko Djurica/Reuters)

Competitors in costume cross a water obstacle during the Wildsau Dirt Run (Wild Boar Dirt Run) obstacle course fun race at Hellsklamm ravine in Obertriesting, Austria, October 22, 2016. (Photo by Heinz-Peter Bader/Reuters)

Syrian refugees covered with dust arrive at the Trabeel border, after crossing into Jordanian territory with their families, near the northeastern Jordanian border with Syria, and Iraq, near the town of Ruwaished, east of Amman September 10, 2015. (Photo by Muhammad Hamed/Reuters)

Gold medalists Kikkan Randall and Jessica Diggins of the United States dancing during the medal ceremony for Cross-Country Skiing – Ladies' Team Sprint Free on day 13 of the PyeongChang 2018 Winter Olympic Games at Medal Plaza on February 22, 2018 in Pyeongchang-gun, South Korea. (Photo by Eric Gaillard/Reuters)

A man reacts to being warned by a British Transport Police officer for not wearing a face mask at King's Cross underground station, London, England on October 8, 2020. (Photo by Jonathan Brady/PA Images via Getty Images)

Riot police wear face masks, as a precautionary measure against the COVID-19 coronavirus, allow a women to cross a cordon after a protest by pro-democracy demonstrators at a shopping mall in Hong Kong on May 9, 2020. (Photo by Isaac Lawrence/AFP Photo)

A Romanian honor guard soldier stands still as three military aircraft carriers are crossing the sky during a ceremony held at the Unknown Soldier Memorial, in Carol I Park, on the occasion of the Heroes' Day commemoration, in Bucharest, Romania, 10 June 2021. (Photo by Robert Ghement/EPA/EFE)

Jordan Mann (R) falls into the water as he and Jordan Cross compete in the first round of Men's 3000 Meters Steeplechase during day four of the 2020 U.S. Olympic Track & Field Team Trials at Hayward Field on June 21, 2021 in Eugene, Oregon. (Photo by Patrick Smith/Getty Images)