An armed man herds his cattle close to the village of Nimini in northern South Sudan, February 8, 2017. In the chaos of South Sudan's civil war, it took three years for Nyagonga Machul to find her lost children. Machul had traveled from her village to the capital when President Salva Kiir, an ethnic Dinka, fired his deputy Riek Machar, a Nuer, in 2013. (Photo by Siegfried Modola/Reuters)

Farmers clash with riot policemen during a protest outside the Greek Agriculture Ministry on March 8, 2017 in Athens, Greece. Two people were detained after the windows of two police vans were smashed as approximately 1,000 farmers, mainly from the island of Crete, took part in the protest. (Photo by Nikolas Georgiou/ZUMA Wire/Rex Features/Shutterstock)

Dancers wait at backstage as they prepare for a dance performance during the Bali Arts Festival in Bali, Indonesia, Wednesday, June 21, 2017. The resort island of Bali is holding a month-long annual Bali Arts Festival from June 10 to July 8. (Photo by Firdia Lisnawati/AP Photo)

Peter Ver Ploeg carries Virginia Petrovek through the mud pit during the North American Wife Carrying Championship, Saturday, October 8, 2016, at the Sunday River Ski Resort in Newry, Maine. (Photo by Robert F. Bukaty/AP Photo)

Jessica Gomes showcases designs by Jessica Gomes for Jets during the David Jones Spring Summer 18 Collections Launch at Fox Studios on August 8, 2018 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images for David Jones)

An Atlantic seal pup lies amongst the rocks at St Martin's Haven, Pembrokeshire, Wales, Britain October 8, 2018. Seal pups are born with fluffy white non-waterproof coats which they moult out in their fourth week. (Photo by Rebecca Naden/Reuters)

Police run past a burning car as they push protesters back during the “yellow vests” demonstration near the Arc de Triomphe on December 8, 2018 in Paris France. “Yellow Vests” (“Gilet Jaunes” or “Vestes Jaunes”) is a protest movement without political affiliation which was inspired by opposition to a new fuel tax. (Photo by Chris McGrath/Getty Images)

Riot police fire tear gas at demonstrators during a protest against fare hikes for city buses in Sao Paulo, Brazil, January 8, 2016. Brazilian riot police on Friday fired tear gas and stun grenades to disperse a violent protest against a rise in public transport fares in the country's largest city, Sao Paulo. (Photo by Nacho Doce/Reuters)