A worker stack bricks on his head at a brick factory in Lalitpur January 12, 2015. (Photo by Navesh Chitrakar/Reuters)

Yan Zhengming (R), 94, and his wife Zhou Suqing (C), 90, attend their wedding ceremony at their home, on the 70th anniversary of their marriage, in Quxian county of Dazhou, Sichuan province, China, May 15, 2015. The wedding, organized by local charity groups, was a long-time wish of veteran of the World War Two Yan, who married Zhou 70 years ago, but could not afford to have a wedding ceremony, local media reported. (Photo by Reuters/Stringer)

Members of the Colombian Navy stand guard on top of a seized submarine built by drug smugglers in a makeshift shipyard in Timbiqui, department of Cauca February 14, 2011. Colombian authorities said the submersible craft was to be used to transport 8 tons of cocaine illegally into Mexico. (Photo by Jaime Saldarriaga/Reuters)

First graders of a cadet's lyceum attend a ceremony to mark the start of the new school year in Kiev, Ukraine, September 1, 2015. September 1 marks the start of a new academic year for students in Ukraine.(Photo by Valentyn Ogirenko/Reuters)

Pakistani supporters of cricketer-turned politician Imran Khan and Canadian cleric Tahir ul Qadri beat a riot policeman during an anti-government protest in Islamabad on September 1, 2014. Hundreds of protesters trying to topple Pakistan's government briefly seized the state broadcaster on September 1, intensifying the political crisis gripping the nuclear-armed nation. Deadly clashes since the weekend have raised the spectre of military intervention which gained ground after one disillusioned opposition leader said the protesters were acting according to a plan devised by the army. (Photo by Aamir Qureshi/AFP Photo)

Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

A Puffing Billy steam train hauled by locomotive 14A crosses the Monbulk Creek trestle after leaving Belgrave station near Melbourne, October 20, 2014. While the discovery of steam power 200 years ago powered the Industrial Revolution, the world long ago shunted most steam trains onto the sidings of history. (Photo by Jason Reed/Reuters)

Cats gather in front of a house damaged by shelling in the town of Dokuchayevsk, south of Donetsk, February 12, 2015. (Photo by Maxim Shemetov/Reuters)