Indonesian students wearing paper masks take part in the East Java Mask Parade in Surabaya, Indonesia, 13 December 2015. Thousands of people participate in the traditional parade to preserve the mask custom among the younger generation. (Photo by Fully Handoko/EPA)

A reveller is tossed into the air as they celebrate the Holi spring festival in Kathmandu on March 12, 2017. The “Holi” festival of colours is a riotous celebration of the coming of spring and falls on the day after the full moon in early March every year. (Photo by Prakash Mathema/AFP Photo)

An Economic Freedom Fighters supporter shows a mock weapons during a demonstration in Pretoria on April 12, 2017 calling for South African President Jacob Zuma to resign. Tens of thousand demonstrators took part in the march to Union Buildings, the official seat of government, which was organised on Zuma's 75th birthday and came after nationwide rallies against the president last week. Zuma's recent sacking of respected finance minister Pravin Gordhan has fanned years of public anger over government corruption scandals, record unemployment and slowing economic growth. (Photo by Marco Longari/AFP Photo)

Musicians of the alphorn band "Holdersberger Alp- Traum- Blaeser" perform their skills on a raft floating on the Elbsee lake near Aitrang, southern Germany, on June 11, 2017. (Photo by Karl-Josef Hildenbrand/AFP Photo/DPA)

A P-51 Mustang named “Charlotte's Chariot” from the Southern Heritage Air Foundation flies past a cloud of smoke and fire from a nearby battle reenactment during the Wings Over Houston Airshow in Houston, on Saturday, November 1, 2014. Battle reenactments are part of the yearly show held at Ellington Airport. (Photo by Kar Hlava/AP Photo/Bay Area Citizen)

Russia's Maria Stavitskaia performs during the ladies short program at the Rostelecom Cup ISU Grand Prix of Figure Skating in Moscow November 14, 2014. (Photo by Grigory Dukor/Reuters)

An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)

Shoppers wrestle over a television as they compete to purchase retail items on “Black Friday” at an Asda superstore in Wembley, north London November 28, 2014. Britain's high streets, malls and online sites were awash with discounts on Friday as more retailers than ever embraced U.S.-style “Black Friday” promotions, seeking to kickstart trading in the key Christmas period. In the United States the Friday following the Thanksgiving Day holiday is called Black Friday because spending usually surges and indicates the point at which American retailers begin to turn a profit for the year, or go “into the black”. (Photo by Luke MacGregor/Reuters)