Romanian military doctors and medical students sit on a bus behind steamy windows before the National Day parade in Bucharest, Romania, Thursday, December 1, 2016. Military planes and helicopters flew over the Romanian capital Thursday as thousands turned out to celebrate the national day, marking the date when the country reunified with Transylvania in 1918. (Photo by Vadim Ghirda/AP Photo)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Costumed participants are seen during an Irish tradition of Hunting of the Wren festival held every St. Stephen's Day in Dingle, Ireland, December 26, 2016. Wren Day, also known as Wren's Day, Day of the Wren, or Hunt the Wren Day is celebrated on 26 December, St. Stephen's Day. The tradition consists of “hunting” a fake wren and putting it on top a decorated pole. (Photo by Clodagh Kilcoyne/Reuters)

Londoners enjoy a “Silent Night” as Big Ben falls silent, London, UK on August 21, 2017. ose Allerston from Clapham, London said “After a stressful day in the office, I couldn't think of anything better than going home and climbing into bed – but when I saw this bed opposite Big Ben I just couldn't resist getting in for a snuggle”. (Photo by Imagewise Ltd/Rex Features/Shutterstock)

Members of the China Disabled Peoples Performing Art Troupe perform “My Dream” at Jorge Eliecer Gaitan Theater in Bogota on August 30, 2017. China Disabled People's Performing Art Troupe Company composed of artists with some hearing, mental, motor, visual or speech disabilities, was founded in 1987 and is currently Honorary and Goodwill Ambassadors of Unesco for its great example of inclusion. (Photo by John Vizcaino/AFP Photo)

Eva Longoria Farmer Visits "The Tonight Show Starring Jimmy Fallon" at Rockefeller Center on November 24, 2015 in New York City. (Photo by Theo Wargo/NBC/Getty Images for "The Tonight Show Starring Jimmy Fallon")

A participant Saint Nicholas parade walks from house to house dressed in the traditional devil and Nicholas costumes in Francova Lhota district of Zlin, Czech Republic on December 3, 2017. This type of parade is one of the most popular age old tradition in a few villages in Wallachia region (eastern part of Czech Republic). Saint Nicholas walks the streets going from house to house three days and Saint Nicholas gives sweets to children and the devils get up to mischief. (Photo by Lukas Kabon/Anadolu Agency/Getty Images)

Riot police clash with demonstrators protesting against proposed pension reforms outside the Congress in Buenos Aires on December 18, 2017. Protesters angry at proposed pension and welfare reforms attacked police close to Argentina's congress building in Buenos Aires on Monday, the second protest in a week to turn violent. Activists lobbed stones, bottles and firecrackers at police as huge crowds demonstrated against pension reforms proposed by the center-right government of President Mauricio Macri. (Photo by Eitan Abramovich/AFP Photo)