South Korean students pose for a selfie following a traditional coming-of-age ceremony at Namsan hanok village in Seoul on May 15, 2017. The Coming of Age Day is the day to celebrate and encourage the youth who have reached the age of 20, which is considered the beginning of adulthood. (Photo by Ed Jones/AFP Photo)

Men slide in the mud during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Saturday, July 22, 2017. The 20th annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)

Children walk past the partially collapsed boundary wall of a school and a Buddhist shrine that were damaged during the earthquake earlier this year at Khumjung, a typical Sherpa village in Solukhumbu district also known as the Everest region, in this picture taken November 30, 2015. (Photo by Navesh Chitrakar/Reuters)

South Korean workers are seen from a crane as they work on the 123rd floor during the framing completion ceremony of the 'Lotte World Tower' in Seoul, South Kora, 22 December 2015. The building's exterior was completed in a final height of 550 meters, and 123 floors. The ceremony came five years and two months after the construction of the building began and its opening will likely take place at the end of next year when the interior work is set to be completed, the South Korean Yonhap news agency reported. The building is the highest in South Korea and the fifth highest in the world, according to Yonhap. (Photo by Jeon Heon-Kyun/EPA)

Samba dancers arrive to perform ahead of the athletics competitions of the 2016 Summer Olympics at the Olympic stadium in Rio de Janeiro, Brazil, Sunday, August 14, 2016. (Photo by Jae C. Hong/AP Photo)

A man with blood on his shirt is evacuated from Brussels Airport in Zaventem, Belgium, on Tuesday, March 22, 2016. (Photo by Dirk Waem/Belga/Zuma Press/TNS)

An ethnic Armenian fighter carries Kalashnikov machine guns to his comrade-in-arms at Martakert province in the separatist region of Nagorno-Karabakh, Azerbaijan, Monday, April 4, 2016. (Photo by Vahan Stepanyan/PAN Photo via AP Photo)

In this March 20, 2016 photo, Maj. Mohammed Hussein, an officer with Iraq's elite counterterrorism forces, shows a photo of a slain Islamic State group militant still wearing in a suicide vest, taken during fighting that freed the city of Ramadi from IS control earlier this year. As they fled, the militants destroyed some buildings and booby-trapped others with explosives, leaving behind an empty prize for government forces retaking the city. (Photo by Maya Alleruzzo/AP Photo)