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)

Tim Anderson final balanced rock stack in the Llano River. Tim Anderson, rock balancing “pro” from Pennsylvania, carefully worked to balance his stack on a dry spot in the Llano river Saturday March 12, 2016. He was an honored guest of the festival and enjoyed visiting Texas so he came for another year. The river was higher this year because of the rains so the balancers could not get to the better rock that were available last year. (Photo by Nell Carroll/American-Statesman)

A woman takes part in a global March for marijuana in Medellin, Colombia, May 7, 2016. The Global Marijuana March (GMM) is an annual rally held at different locations across the planet. It refers to cannabis-related events that occur on the first Saturday in May, or thereabouts, and may include marches, meetings, rallies, raves, concerts, festivals and information tables. (Photo by Fredy Builes/Reuters)

Covered in prayer shawls, Ultra-Orthodox Jewish men participate in a blessing during the holiday of Sukkot, in front of the Western Wall, the holiest site where Jews can pray in Jerusalem's Old City, Wednesday, September 30, 2015. The Cohanim, believed to be descendants of priests who served God in the Jewish Temple before it was destroyed, perform a blessing ceremony of the Jewish people three times a year during the festivals of Passover, Shavuot and Sukkot. (Photo by Oded Balilty/AP Photo)

This picture taken on July 8, 2015 shows 13-year-old jockey Purevsurengiin Togtokhsuren (R) watching a horse rolling in the dirt after a training session in Khui Doloon Khudag, some 50 kms west of Ulan Bator. Despite being only 13 years old, Togtokhsuren is riding for the fifth time in the national races for Mongolia's summer festival, known as Naadam, lining up against some 170 other child jockeys. (Photo by Johannes Eisele/AFP Photo)

A Pakistani devotee dances to celebrate the three-day annual festival to pay tribute to the famous saint Al-Sheikh Ali Bin Usman Al-Hajveri known as Data Ganjbaksh at outside his shrine in Lahore, Pakistan, Sunday, November 20, 2016. Thousands of people traveled from all over Pakistan to attend the celebrations. (Photo by K.M. Chaudary/AP Photo)

Fireworks explode over the Kremlin in Red Square which was blocked by police during New Year celebrations in Moscow, Russia, Sunday, January 1, 2017. New Year's Eve is Russia's major gift-giving holiday, and big Russian cities were awash in festive lights and decorations. (Photo by Alexander Zemlianichenko Jr./AP Photo)

The Viking longboat burns during the annual Up Helly Aa festival in Lerwick, Shetland Islands, on January 28, 2014. Up Helly Aa celebrates the influence of the Scandinavian Vikings in the Shetland Islands and culminates with up to 1,000 “guizers” (men in costume) throwing flaming torches into their Viking longboat and setting it alight later in the evening. (Photo by Andy Buchanan/AFP Photo via Getty Images)