A pilgrim walks on her knees to fulfil her vows, as pilgrims attend the 99th anniversary of the appearance of the Virgin Mary to three shepherd children, at the Catholic shrine of Fatima, Portugal May 12, 2016. (Photo by Rafael Marchante/Reuters)

An invalis asking alms walks past a girl posing for the picture in the center of Ukrainian capital of Kiev on August 17, 2016. (Photo by Sergei Supinsky/AFP Photo)

Smoke plumes rise from Mount Etna, one of the most active volcanoes in the world in Sicily, Italy on June 28, 2016. (Photo by Etna Walk/Rex Feature/Shutterstock)

A woman selling souvenirs walks through Kuta beach in Bali June 5, 2008. Indonesia is expected to report tourist arrivals in December this week. (Photo by Murdani Usman/Reuters)

An actress dressed as Wonder Woman walks between visitors during the season inauguration of the Madrid Warner amusement park in San Martin de Valdeiglesias, near Madrid, Spain, March 18, 2016. (Photo by Andrea Comas/Reuters)

People walk past a man preaching along a train track in Ikeja district in Nigeria's commercial capital Lagos April 12, 2016. (Photo by Akintunde Akinleye/Reuters)

A model walks the runway at the Christian Siriano X Lane Bryant Collection at United Nations on May 9, 2016 in New York City. (Photo by JP Yim/Getty Images)

Women walk past a pile of rubbish bags on a street during a strike by garbage collectors demanding delayed salaries in Sanaa, Yemen May 8, 2017. (Photo by Khaled Abdullah/Reuters)