Saudi children of al-Fefi family walk up the stairs as they make their way to their schools through Fifa Mountain, in Jazan, south of Saudi Arabia, December 15, 2016. (Photo by Mohamed Al Hwaity/Reuters)

Habimana, 45, and her children walk to market to sell pottery on Idjwi island in the Democratic Republic of Congo, November 23, 2016. (Photo by Therese Di Campo/Reuters)

Shoppers walk past crocodiles for sale at a market in Bata on February 3, 2015. Markets in Equatorial Guinea sell a variety of animals including pangolins, monkeys and crocodiles as food. (Photo by Carl de Souza/AFP Photo)

A model walks the runway for Chromat during New York Fashion Week: The Shows at Industria Studios on February 9, 2018 in New York City. (Photo by Noam Galai/Getty Images for Chromat)

Elephant Maja of Circus Bush on his daily walk with Circus ringmaster Hardy Scholl (R) on Berlin streets in Berlin, Germany June 30, 2016. (Photo by Stefanie Loos/Reuters)

A man carries floats as he walks on an algae covered beach as a truck collecting algae passes by, along the coastline in Qingdao, Shandong province, July 6, 2015. (Photo by Reuters/China Daily)

A person dressed like a zombie walks during the 2015 Comic-Con International Convention in San Diego, California July 9, 2015. The pop-culture held at the San Diego Convention Center event runs July 9-12. (Photo by Mario Anzuoni/Reuters)

A woman holds her umbrella while walking against strong winds as Typhoon Chan-hom approaches Taiwan, in Taipei, July 10, 2015. (Photo by Pichi Chuang/Reuters)