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)

Tarah Kayne and Daniel O'Shea of the U.S. perform during the Pairs short program at the Skate America figure skating competition in Milwaukee, Wisconsin October 23, 2015. Fifty-six Olympic and world championship athletes are competing in the event, which is the first of six stops on the International Skating Union (ISU) Grand Prix of Figure Skating Series. (Photo by Lucy Nicholson/Reuters)

Vendors selling vegetables wait for customers under a flyover in the early morning in Ahmedabad, India on February 1, 2017. (Photo by Amit Dave/Reuters)

A dog walker on Longsands beach before sunrise in Tynemouth, UK on April 1, 2016. (Photo by Owen Humphreys/PA Wire)

Festival crowd enjoying the weather on Day 1 of Reading Festival on August 25, 2017 in Reading, England. (Photo by Dean Fardell/Barcroft Images)

Lightning strikes near Jacobsdorf at the Oder-Spree district in eastern Germany, September 1, 2015. (Photo by Patrick Pleul/AFP Photo)

Performers eat their lunch before the start of the New Year's Day Parade in London, January 1, 2016. (Photo by Kevin Coombs/Reuters)

A tamed hawk sits on a chair next to a participant during a traditional hunting contest in Almaty, Kazakhstan on December 1, 2018. (Photo by Pavel Mikheyev/Reuters)