South Vietnamese forces escort suspected Viet Cong officer Nguyen Van Lem (also known as Bay Lop) on a Saigon street February 1, 1968, early in the Tet Offensive. Moments later, Lem was executed by Gen. Nguyen Ngoc Loan, chief of the national police. (Photo by Eddie Adams/AP Photo)

A dog, at the behest of his owner, rides a skatebaord on April 3, 2017 in Berlin, Germany. The dog's owner, who looked like he might be homeless, coaxed the dog to ride the skatebaord and asked passersby who stopped to watch for money. (Photo by Sean Gallup/Getty Images)

British model Jourdan Dunn arrives for the premiere of “The Killing of a Sacred Deer” during the 70th annual Cannes Film Festival, in Cannes, France, 22 May 2017. The movie is presented in the Official Competition of the festival which runs from 17 to 28 May. Dress by Elie Saab Haute Couture. (Photo by Julien Warnand/EPA)

United States' Inika McPherson prepares an attempt during the women' s high jump final during the World Athletics Championships in London Saturday, August 12, 2017. (Photo by Kai Pfaffenbach/Reuters)

A cat dressed in a traditional Ukrainian embroidered shirt takes part in a parade in Kiev, Ukraine on May 28, 2016. (Photo by Gleb Garanich/Reuters)

North Korean children wave to people on a Chinese tourist boat on the banks of Yalu River near the Chongsong county of North Korea, opposite the Chinese border city of Dandong, May 8, 2011. (Photo by Jacky Chen/Reuters)

Snow covers roofs, streets and the Charles River following a winter blizzard in Boston, Massachusetts January 28, 2015. A powerful blizzard struck Boston and surrounding New England on Tuesday, leaving some 4.5 million people grappling with as much as three feet of snow and coastal flooding. (Photo by Brian Snyder/Reuters)

Singer Ariana Grande performs during the 2014 MTV Europe Music Awards at the SSE Hydro Arena in Glasgow, on November 9, 2014. (Photo by Toby Melville/Reuters)