A South Korean marine in action during their regular drill on Yeonpyeong Island, South Korea November 1, 2018. (Photo by Jeon Heon-Kyun/Pool via Reuters)

Cooler temperatures begin this week as a polar vortex brings much colder conditions with the chance of snow for Snowdonia, Ogwen Valley, North Wales on 22nd October 2018. The Ogwen Valley and Tryfan Mountain looking splendid in the Autumn sunrise. (Photo by DGDImages/Alamy Live News)

A man passes at the displayed art installation “Middle way” by Romanian artist Bogdan Rata in Kiev, Ukraine, Tuesday, November 20, 2018. The monument set on the central Kiev street of Khreshchatyk, at the place of Vladimir Lenin monument which was destroyed in 2013 during the Maidan events. (Photo by Efrem Lukatsky/AP Photo)

A Flemish demonstrator, one of thousands who gathered for a march through Brussels to protest against what the Flemings call their subjucation by the French-speaking Walloons, draws back as he is jeered by a crowd of Walloons on the pavement in a Brussels Street, on October 14, 1962. The Flemish demonstrators clashed with Walloon counter demonstrators as riot police sought to maintain order. The Flemings claim that although they form 60% of the population in Belgium, they are inadequately represented in the government, and they say, the Walloons get most of the top jobs in the armed forces and the diplomatic service. (Photo by AP Photo)

In this April 28, 2015 file photo, heads of tuna on a cart are carried by a fish dealer after the day's auction at Tsukiji Wholesale Market in Tokyo. In one of the biggest of Japan's many New Year holiday rituals, early on Tuesday, January 5, 2016, Tokyo's Tsukiji market will auction off with much fanfare a huge, glistening tuna, likely destined for one of the big sushi chains. If all goes as planned, it will be the last such auction at 80-year-old Tsukiji. (Photo by Shuji Kajiyama/AP Photo)

A woman walks inside a building in downtown Havana, Cuba April 21, 2016. (Photo by Alexandre Meneghini/Reuters)

People are reflected in mirrors as they walk in a busy shopping district in Tokyo, Japan, December 25, 2015. (Photo by Thomas Peter/Reuters)

Cyclists compete during the UCI BMX World Championships Elite Women's Moto Race on May 29, 2016 in Medellin, Antioquia department, Colombia. (Photo by Raul Arboleda/AFP Photo)