Students from St Andrews University are covered in foam as they take part in the traditional “Raisin Weekend” in the Lower College Lawn, at St Andrews in Scotland, Britain October 17, 2016. The weekend, which begins on Sunday, involves rituals for new students, culminating in a foam fight on Monday morning. (Photo by Russell Cheyne/Reuters)

A Nepalese woman pours milk as she offers prayers to the setting Sun on the banks of the Bagmati River during the Chhath Puja festival in Kathmandu, Nepal, Sunday, November 6, 2016. During Chhath, an ancient Hindu festival, rituals are performed to thank the Sun God for sustaining life on earth. (Photo by Niranjan Shrestha/AP Photo)

Passengers prepare to take part in the No Pants Subway Ride in Prague, Czech Republic, Sunday, January 8, 2017. The No Pants Subway Ride began in 2002 in New York as a stunt and has taken place in cities around the world since then. (Photo by Petr David Josek/AP Photo)

Girls take part in the traditional seasonal Christmas run along the streets of Vilnius, Lithuania, Sunday, December 17, 2017. The festive run attracts many hundreds of people to the capital dressed as Santa Clause to take part in the sporting event. (Photo by Mindaugas Kulbis/AP Photo)

A paddler races in a giant pumpkin during the annual regatta on Lake Pisiquid in Windsor, Nova Scotia, Sunday, October 11, 2015. Participants hollow out the massive gourds and pilot them across the 500 meter course. (Photo by Andrew Vaughan/The Canadian Press via AP Photo)

An activist takes a selfie during a protest ahead of the 2015 Paris Climate Conference, in Paris, Sunday, November 29, 2015. More than 140 world leaders are gathering around Paris for high-stakes climate talks that start Monday, and activists are holding marches and protests around the world to urge them to reach a strong agreement to slow global warming. (Photo by Christophe Ena/AP Photo)

A trapped car is pushed along a flooded street after typhoon Soudelor hit Fuzhou, Fujian province, China, August 9, 2015. The typhoon battered China's east coast on Sunday, killing eight people and forcing authorities to cancel hundreds of flights and evacuate more than 163,000 people. (Photo by Reuters/Stringer)

Fireworks explode above St. Basil's cathedral during a rehearsal for the “Spasskaya Tower” international military music festival at Moscow's Red Square, September 4, 2015. Military bands from different countries will participate in the annual tattoo starting on Sunday. (Photo by Maxim Zmeyev/Reuters)