A woman carries a piglet as she runs on ice during a running challenge in Changsha, Hunan province February 8, 2015. A total of 20 people participated in the challenge requiring them to choose a pig ranging between 15 kg and 115 kg in weight, and carrying it while running on a 20.15-metre-long ice track. The participants that complete the challenge will be rewarded with the pig they carried, local media reported. (Photo by Darwin Zhou/Reuters)

Hindu devotees, their bodies pierced with lemon and paladai, or bowl with a spout mainly used to feed milk to infants, wait to participate in a procession to mark Shivratri, or the night of Shiva, in Chennai, India, Wednesday, February 18, 2015. Such processions are held as an offering and show of devotion by devotees on the day dedicated to the worship of Lord Shiva, the Hindu god of destruction. (Photo by Arun Sankar K./AP Photo)

South Korean police officers show their martial arts' skills during the official launch ceremony of the 2012 Seoul Nuclear Security Summit on February 15, 2012 in Seoul, South Korea. The Korean National Police Agency launched a security squad, exclusively established for the successful hosting of the 2012 Seoul Nuclear Security Summit. The 2012 Seoul Nuclear Security Summit will be held in Seoul from March 26-27, 2012. (Photo by Chung Sung-Jun/Getty Images)

A commuter gestures to Boris Johnson as he rides across Vauxhall Bridge in London, England on November 19, 2015. The London mayor was opening a cycle superhighway. (Photo by John Stillwell/PA Wire)

Mercedes Formula One driver Lewis Hamilton of Britain sprays champagne at a grid girl as he celebrates his victory on the podium after the Chinese F1 Grand Prix at the Shanghai International Circuit, April 12, 2015. (Photo by Carlos Barria/Reuters)

A diesel locomotive has ended up in the river Venoge on March 8, 2013 near Penthalaz, Western Switzerland. The freight locomotive derailed near Cossonez railway station with its driver slightly injured. (Photo by Fabrice Coffrini/AFP Photo)

A Libyan fireman stands in front of smoke and flames rising from an oil storage tank at an oil facility in northern Libya's Ras Lanouf region on January 23, 2016, after it was set ablaze earlier in the week following attacks launched by Islamic State (IS) group jihadists to seize key port terminals. (Photo by AFP Photo/Stringer)

A group of young men use a selfie stick to take a picture of themselves in shallow waters known as the first cataract of the River Nile outside Khartoum, Sudan, May 22, 2015. In Sudan, which faces insurgences in the western region of Darfur and along its border with breakaway South Sudan, as well as double-digit inflation and high unemployment, life goes on for young people in the capital Khartoum. (Photo by Mohamed Nureldin Abdallah/Reuters)