Two carnival revellers masquerade as Leonardo da Vinci's painting “Mona Lisa” pose in St. Mark's Square in Venice, Italy, Sunday, January 31, 2016. Carnival-goers in Venice are being asked by police to momentarily lift their masks as part of new anti-terrorism measures for the annual festivities. (Photo by Domenico Stinellis/AP Photo)

Musher Justin Savidis' dogs wait in the truck before the restart of the Iditarod Trail Sled Dog Race in Willow, Alaska March 6, 2016. Mushers and dog sled teams from around the world embark on the first leg of Alaska's grueling Iditarod Trail Sled Dog Race, starting a nearly 1,000-mile (1,609 km) journey through the state's unforgiving wilderness. (Photo by Nathaniel Wilder/Reuters)

A reveller dressed up as Austrian drag queen and 2014 Eurovision song contest winner Conchita Wurst takes part in New Year's celebrations in Coin, near Malaga, southern Spain, early January 1, 2015. Villagers and revellers dressed up in funny costumes to take part in the New Year's celebration. (Photo by Jon Nazca/Reuters)

Dancers perform on their way to attend a rally with former President Luiz Inacio Lula da Silva, “Lula”, supporting President Dilma Rousseff in the historic Lapa neighborhood on April 11, 2016 in Rio de Janeiro, Brazil. Brazil's congressional impeachment committee approved the motion to proceed with President Dilma Rousseff's impeachment process today. A full vote by the lower house of Congress on the impeachment is scheduled for Sunday to decide whether she will face trial. (Photo by Mario Tama/Getty Images)

A herdsman stands on the back of a grey bull during a ceremony of driving sheep from their winter habitat to their summer pasture in the puszta or Hungarian steppe of Hortobagy, 183 kms east of Budapest, Hungary, 23 April 2016. Sheep are traditionally driven to their summer pasture at around St. George's Day in the Hortobagy region, because livestock breeding people traditionally consider St. George's Day the beginning of spring. (Photo by Zsolt Czegledi/EPA)

A policeman reacts during a clash with protestors during a protest against the proposed changes to France's working week and layoff practices, in Lyon, central France, Thursday, April 28, 2016. French protesters are back on the streets over proposed reforms to the country's labor rules and strikers have forced cancellations and delays at two airports serving Paris. (Photo by Laurent Cipriani/AP Photo)

The newest Victoria's Secret “Angels” models pose for photographers in New York's Times Square during the launch of the new “Body by Victoria” campaign July 28, 2015. From L-R front row are Elsa Hosk, Martha Hunt, Sara Sampaio, Jasmine Tookes and Stella Maxwell. From L-R back row are Kate Grigorieva, Taylor Hill, Rommee Strijd, Jac Jagaciak and Lais Ribeiro. (Photo by Mike Segar/Reuters)

An Afghan policeman stands guard as smoke and flames rise from the site of a huge blast struck near the entrance of Kabul's international airport, in Kabul on August 10, 2015. A huge blast struck near the entrance of Kabul's international airport on August 10 during the peak lunchtime period, officials said, warning that heavy casualties were expected. “The explosion occurred at the first check point of Kabul airport”, said deputy Kabul police chief Sayed Gul Agha Rouhani. (Photo by Shah Marai/AFP Photo)