People of pro-government groups, with Russian flags, dance marching through downtown Moscow to mark People's Unity Day, a public holiday, in Russia, on Tuesday, November 4, 2014. Russia marks National Unity Day on November 4 to celebrate the defeat of Polish invaders in 1612. (Photo by Ivan Sekretarev/AP Photo)

A man dressed in a traditional Perchten costume and mask performs during a Perchten festival in the western Austrian village of Huben November 22, 2014. Each year in November and January people in the western Austria regions dress up in Perchten (also known in some regions as Krampus or Tuifl) costumes and parade through the streets to perform a 1,500 year-old pagan ritual to disperse the ghosts of winter. (Photo by Dominic Ebenbichler/Reuters)

Prospective flight attendants listen to their instructor during an etiquette training course at Indigo Airlines' Ifly training centre in Gurgaon on the outskirts of New Delhi November 18, 2014. (Photo by Adnan Abidi/Reuters)

Demonstrators confront riot police during clashes in central Brussels November 6, 2014. Tens of thousands of public and private sector workers, employees and trade union members demonstrated over austerity measures to be taken by the new Belgian government. (Photo by Francois Lenoir/Reuters)

Pawel Karpinski and Nadine Kinczel of Poland dance as they compete during IPC Wheelchair Dance Sport European Championships in Lomianki near Warsaw, November 9, 2014. (Photo by Kacper Pempel/Reuters)

Couples participate in the “Running of the Brides” race in a park in Bangkok November 29, 2014. Seventy-five husbands and wives-to-be wore their wedding dresses and running shoes and competed in an event for a combined prize worth 1 million Thai baht ($30,460). (Photo by Damir Sagolj/Reuters)

Polar bear twins make their first public appearance with their mother “Freedom” at Ouwehands Zoo Rhenen, in Rhenen, The Netherlands, 19 February 2015. The twins, who were born in November 2014, have not been named because their gender has not yet been determined. (Photo by Bart Maat/EPA)