A weeping South Vietnamese mother and her three children are shown on the deck of this amphibious command ship being plucked out of Saigon by U.S. Marine helicopters in Vietnam, April 29, 1975. (Photo by AP Photo)

A nurse consoles herself with a box of chocolates as she reads a paper-back thriller. (Photo by Hulton Archive/Getty Images). Circa 1955

Boards stand lined up at the Rocinha Surf Association, ASR, headquarters at Rocinha slum in Rio de Janeiro, Brazil, Thursday, July 2, 2015. ASR has given free lessons to over 2,000 children from Rio's shantytowns in the hopes of keeping the boys, who are mostly in their early teens and a few girls occupied by the sport and off the streets. (Photo by Felipe Dana/AP Photo)

Riot police fire tear gas during a protest by supporters of Dilma Rousseff in Sao Paulo, Brazil August 31, 2016. (Photo by Paulo Whitaker/Reuters)

Children play football in Bujumbura, Burundi on March 19, 2015. (Photo by Carl de Souza/AFP Photo)

Models wait backstage during the Ukrainian Fashion Week in Kiev, October 16, 2015. (Photo by Valentyn Ogirenko/Reuters)

A man hugs a child at the Santuario de Nuestra Senora de Guadalupe during a celebration on the Virgin of Guadalupe Day in Guatemala City, December 12, 2015. According to Catholic believers, December 12 marks the anniversary of the apparition of the Virgin of Guadalupe at the Cerro del Tepeyac in Mexico. (Photo by Jorge Dan Lopez/Reuters)

Lightning illuminates a thundercloud as a storm front hits the North Sea region near Westerhever, northern Germany, on August 11, 2014. (Photo by Daniel Reinhardt/AFP Photo/DPA)