Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

A girl rides a donkey as another walks by at the Shawqaba camp for internally displaced people who were forced to leave their villages by the war in Yemen's northwestern province of Hajjah March 12, 2016. In northwest Yemen, one of the poorest countries in the Middle East, about 400 families uprooted by the war have been stuck in the Shawqaba camp in Hajjah province for the past year. Residents live in poorly built huts that protect them neither from summer heat nor winter cold in a camp that lacks the most basic services. (Photo by Abduljabbar Zeyad/Reuters)

White smoke billowed from the chimney on the Sistine Chapel indicating that a new pope has been elected in St. Peter's Square at the Vatican, Wednesday, March 13, 2013. (Photo by Dmitry Lovetsky/AP Photo)

These two young siblings appear to cling on to a tree for dear life and even hold hands as they learn the ropes of climbing, on June 25, 2013. (Photo by Tim Fitzharris/Minden/Solent)

A representative of Makinarium production, specialized in special visual effects, displays a latex mask for horror movie on a stand inside the Festival Palace during the 69th Cannes Film Festival in Cannes, France, May 14, 2016. (Photo by Regis Duvignau/Reuters)

Female members of the Chinese People's Liberation Army (PLA) honour guard stand behind a string to ensure that they are in a straight line before a welcoming ceremony for Russian President Vladimir Putin outside the Great Hall of the People in Beijing, China, June 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Visitors hold ice blocks to cool themselves in hot weather at a water park on June 23, 2016 in Chongqing, China. Citizens and visitors escaped high temperature at a water park in Yangren Jie (also known as Foreigner Street), Nan'an District of south China's Chongqing. (Photo by VCG/VCG via Getty Images)

MTV Ex On The Beach and reality TV Star Jemma Lucy is spotted keeping herself in shape with a workout session in a park in Manchester, UK on September 2, 2016. (Photo by XposurePhotos.Com)