A boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

A girl gets her hands decorated with traditional henna patterns at a roadside stall ahead of Eid-al Fitr to mark the end of the holy fasting month of Ramadan in Karachi, Pakistan, July 17, 2015. (Photo by Akhtar Soomro/Reuters)

An animal rights activist washes herself with red dye to mimic blood during a protest against the testing of shampoo on animals in Barcelona. April 24, 2012. (Photo by Raul Albaledo/AFP Photo)

A worker walks through a salt pan on the eve of May Day or Labour Day on the outskirts of the southern Indian city of Chennai April 30, 2014. India is the third largest salt producing country in the world after China and U.S. with global annual production about 230 million tonnes, according to government data. (Photo by Reuters/Babu)

Fearless daredevils clamber up the worlds highest man-made climbing wall – running up the face of a 540ft dam. The Diga di Luzzone in Switzerland is considered by climbers as the Everest of wall climbing. (Photo by Ilana Marcus/Caters News)

An athlete pulls a 15-tonne truck during a Truck-Pull event marking the upcoming Independence Day in the Belarus capital Minsk, on July 3, 2014. The former Soviet nation celebrates its Independence Day on July 3 in memory of the end of Belarus occupation by Nazi Germany troops during the Red Army main summer offensive in 1944. (Photo by Sergei Gapon/AFP Photo)

German fan Didi Senft known as El Diablo cheers as the pack rides past during the 234.5 km seventh stage of the 101st edition of the Tour de France cycling race on July 11, 2014 between Epernay and Nancy, northeastern France. (Photo by Lionel Bonaventure/AFP Photo)