Protesters use fireworks against riot police during clashes in the Athens neighborhood of Exarchia, a haven for extreme leftists and anarchists, Thursday, December 6, 2018. New protest marches were underway in Greece Thursday evening on the 10th anniversary of the fatal police shooting of a teenager, hours after violent initial demonstrations where masked youths attacked police with firebombs and stones. (Photo by Yorgos Karahalis/AP Photo)

An exhibitor takes a photo with a Huawei Mate 10 Pro during the 2018 CES in Las Vegas, Nevada, U.S. January 9, 2018. CES, the world's largest annual consumer technology trade show, runs through January 12 and features about 3,900 exhibitors showing off their latest products and services to more than 170,000 attendees. (Photo by Steve Marcus/Reuters)

A performer takes part in a night parade to celebrate Chinese New Year in Hong Kong Friday, February 16, 2018. The Lunar New Year this year marks the Year of the Dog in the Chinese calendar. (Photo by Vincent Yu/AP Photo)

Revellers celebrate “Ash Monday” by participating in a colourful “flour war”, a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter, in Galaxidi, Greece February 19, 2018. (Photo by Alkis Konstantinidis/Reuters)

A young woman flashes the victory sign in front of a bonfire as Turkish Kurds gather during Newroz celebrations for the new year in Diyarbakir, southeastern Turkey, on March 21, 2018. Newroz (also known as Nawroz or Nowruz) is an ancient Persian festival, which is also celebrated by Kurdish people, marking the first day of spring, which falls on March 21. (Photo by Ilyas Akengin/AFP Photo)

Girls in swimsuits participate in the Grelka Fest at the ski resort Sheregesh in Tashtagolsky District of Kemerovo Oblast, Russia on April 15, 2018. Skiers and snowboarders from around the world marked the end of the 2017-18 winter season. Wearing bikinis and bathing shorts a total of 1,525 claimed a new Russian record for the daring downhill escapade – in a temperature of around 5ºC. In fact, more have taken part in this GrelkaFest event in the past, but not during an official record attempt. (Photo by Kemerovo Online/The Siberian Times)

Women dressed up as Vikings attend the annual Viking festival of Catoira in north-western Spain on August 5, 2018. The festival re-enacts past Viking raids in the area and is celebrated annually on the first Sunday of August. (Photo by Miguel Vidal/Reuters)

Participants dressed as cuddly animals arrive for the annual Eurofurence “furries” gathering at the Estrel hotel on August 22, 2018 in Berlin, Germany. Eurofurence attracts furry fandom enthusiasts from across the globe for four days of anthropomorphic fun. (Photo by Michele Tantussi/Getty Images)