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 man dressed as Father Frost, Russian equivalent of Santa Claus, sits by the fire with a reindeer Yakut, marking winter solstice at the Royev Ruchey Park of Flora and Fauna in the Siberian Taiga wood in the suburbs of Krasnoyarsk, Russia, December 21, 2016. (Photo by Ilya Naymushin/Reuters)

America in the 1970s: Texas. Motorcyclist loading his possessions onto a truck with the help of his friends in Leakey, May 1973. (Photo by Marc St. Gil/NARA via The Atlantic)

The British rock and roll group the Beatles talk to Ed Sullivan at CBS Studio 50 before their live television appearance on “The Ed Sullivan Show” in New York, February 10, 1964. From left to right are, Sullivan, John Lennon, Ringo Starr, holding a cigarette, and Paul McCartney. (Photo by AP Photo)

An election poster calling for the legalisation of marijuana and featuring internet meme “Grumpy Cat” hangs outside the Pirate Party's campaign headquarters in Berlin on August 16, 2013. The Pirates, who to everyone's surprise were elected into Berlin's regional parliament in September 2011, are trying to capitalise on their recent electoral gains in upcoming parliamentary elections, running on a platform of transparency in government. Germany goes to the polls on September 22, 2013. Placard reads: “Hurry up, my dope is everything”. (Photo by John Macdougall/AFP Photo)

Visitors crowd an artificial wave swimming pool at a tourist resort to escape the summer heat in Daying county of Suining, Sichuan province, China, July 11, 2015. (Photo by Reuters/Stringer)

Russia's synchronised swimming duet Aleksandr Maltsev (L) and Darina Valitova compete in the Mixed Duet Technical preliminary during the synchronised swimming competition at the 2015 FINA World Championships in Kazan on July 25, 2015. (Photo by Christophe Simon/AFP Photo)