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

Mud-covered tourists pretend to be trapped inside a mud prison at the Daecheon Beach Mud Plaza in the city of Boryeong on South Korea's west coast, July 17, as they take part in the Boryeong Mud Festival, which opened that day and runs through July 26. Boryeong mud is rich in natural mineral component and is considered to prevent skin aging. (Photo by EPA/Yonhap)

Four hundred buyers from around the world join 260 diamond manufacturing and trading firms on International Diamond Week as some 1,500 people are expected to trade more than billion of polished diamonds this week in Ramat Gan, Israel on February 16, 2016. The Israel Diamond Exchange is considered the most secure in the world, covering an area of 100,000 square meters with 3,500 bourse members. (Photo by Nir Alon via ZUMA Wire)

Indonesian residents look at the Mount Sinabung volcano as it spews volcanic ash near the Tiga Pancur village in Karo, North Sumatra on August 3, 2016. Volcanic eruptions in Indonesia in recent days have forced the closure of two airports and disrupted some flights to the holiday island of Bali, officials said August 3. Mount Sinabung, a volcano on the western island of Sumatra which has been rumbling for some time, also erupted violently on August 2, although its ash clouds did not disrupt any flights. (Photo by Y.T. Haryono/AFP Photo)

Nepal's Kumari, or living goddess, adjusts her ornament as she watches the Rato Machindranath chariot Festival in Lalitpur, Nepal, Friday, April 24, 2015. Nepal's living goddesses are young pre-pubescent girls considered by devotees to be incarnations of a Hindu goddess. Selected as toddlers, living goddesses usually keep their positions until they reach puberty. (Photo by Niranjan Shrestha/AP Photo)

A 22-year-old woman in a wedding gown is grabbed by Guo Zhongfan, a local community officer, as she attempts to kill herself by jumping out of a seven-storey residential building in Changchun, Jilin province. According to local media, the woman tried to commit suicide after her boyfriend of four years broke up with her, just as they were making plans to get married. The woman did not sustain any injuries during the incident. (Photo by China Daily/Reuters)

Kirby Chambliss of the United States flies in formation with Matt Hall of Australia, Yoshihide Muroya of Japan and Nigel Lamb of Britain prior to the third stage of the Red Bull Air Race World Championship in front of the Petronas Towers in Kuala Lumpur, Malaysia, on May 15, 2014. (Photo by Joerg Mitter/Red Bull via Reuters)

A tattoo artist applying ink on a girl's thigh at the 2016 Italian Tattoo Artists at the Palavela on September 17, 2016 in Turin, Italy. (Photo by Stefano Guidi/ZUMA Press/Splash News)