A boy plays with pelicans in Yoff, commune of Dakar, Senegal March 14, 2018. (Photo by Zohra Bensemra/Reuters)

Indigenous Sahrawi girls play on an improvised see-saw at a refugee camp of Boudjdour in Tindouf, southern Algeria March 3, 2016. UN Secretary General Ban Ki-moon is scheduled to visit the Sahrawi refugees in south-west Algeria's Tindouf region. (Photo by Zohra Bensemra/Reuters)

A girl is seen in a bakery in the old walled town of Harar in eastern Ethiopia, May 19, 2015. Daily life of people in Ethiopia, where elections are held this weekend, is portrayed in the east African nation's churches and mosques, coffee shops and markets, both in the capital Addis Ababa and the walled town of Harar in the east. Ethiopia, home to nearly 100 million people, holds the first poll on Sunday since long-serving leader Meles Zenawi died in 2012. (Photo by Siegfried Modola/Reuters)

Participants take pictures of themselves as others run past the Tiananmen gate during the Beijing Marathon in Beijing, China, September 17, 2016. (Photo by Damir Sagolj/Reuters)

Revellers take a break during the Carnival 2016 parade in Port-au-Prince, Haiti, February 8, 2016. (Photo by Andres Martinez Casares/Reuters)

Scarlett points at the huge ice sculpture of a bear during a Photocall for Magical Ice Kingdom at Hyde Park Winter Wonderland at Hyde Park on November 17, 2016 in London, England. It is the event's 10th anniversary this year. (Photo by Ben Perry/Getty Images)

A Zimbabwean subsistence farmer holds a stunted maize cob in his field outside Harare, January 20, 2016. About 14 million people face hunger in Southern Africa because of a drought that has been exacerbated by an El Nino weather pattern, the United Nations World Food Programme (WFP) said on Monday. In Zimbabwe, 1.5 million people, more than 10 percent of the population, face hunger, WFP said. (Photo by Philimon Bulawayo/Reuters)

A hot air ball balloon floats past while people stand in line to climb the Pyramid of the Sun and welcome the spring equinox in the pre-hispanic city of Teotihuacan, on the outskirts of Mexico City, Mexico, March 20, 2016. Spring equinox in Teotihuacán is an annual event which takes place around the 20th and 21st of March at the pre-Hispanic site of Teotihuacán, Mexico. This event is mirrored by other similar events in other pre-Hispanic sites such as Chichén Itzá and Malinalco, Mexico State. (Photo by Edgard Garrido/Reuters)