A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

Children stand in a boat at the banks of the polluted Yamuna River during a dust haze as they wait to give a ride to worshippers in New Delhi during World Environment Day June 5, 2010. (Photo by Reinhard Krause/Reuters)

Ukrainian President Petro Poroshenko gestures during a news conference in Kiev, Ukraine, June 5, 2015. REUTERS/Mykhailo Markiv/Ukrainian Presidential Press Service/Pool

Female soldiers with their faces painted in the colours of the Venezuelan flag, march during a military parade to celebrate the anniversary of Venezuela's independence in Caracas, July 5, 2015. (Photo by Jorge Dan Lopez/Reuters)

Toyota driver Rainer Wissmans of Germany drives during the 2nd stage of the Dakar Rally 2015, from Villa Carlos Paz to San Juan January 5, 2015. (Photo by Jean-Paul Pelissier/Reuters)

A trader weighs tobacco at a market in el-Fasher, in North Darfur February 5, 2015. Tobacco is one of the North Darfur war zone's main cash crops. (Photo by Mohamed Nureldin Abdallah/Reuters)

A giant storm cloud can be seen in the sky above swimmers near Mollymook Beach, south of Sydney, March 5, 2014. (Photo by David Gray/Reuters)

A boy runs next to a portrait of Thailand's King Bhumibol Adulyadej, placed in celebration of the King's 88th birthday, in Bangkok, Thailand, December 5, 2015. (Photo by Jorge Silva/Reuters)