Children displaced as a result of Boko Haram attacks in the northeast region of Nigeria, run at a camp for internally displaced persons (IDP) in Yola, Adamawa State January 13, 2015. Boko Haram says it is building an Islamic state that will revive the glory days of northern Nigeria's medieval Muslim empires, but for those in its territory life is a litany of killings, kidnappings, hunger and economic collapse. (Photo by Afolabi Sotunde/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)

Businesswoman and vendor Sonia Maria Paypay sells clothing at a stand at the commercial zone of Gamarra in Lima, April 16, 2015. (Photo by Mariana Bazo/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)

Construction workers take a lunch break on a steel beam atop the RCA Building at Rockefeller Center, New York, September 29, 1932. In the background is the Chrysler Building. (Photo by AP Photo)

Master of throat singing (or Khoomei) Aikhan Orzhak (L) and model Choigana Kertek, dressed in traditional costume, perform during sunset at the Aldyn Bulak area on the bank of the Yenisei River outside the village of Ust-Elegest in Tuva region, Southern Siberia, Russia, October 7, 2015. The region is inhabited by Tuvans, historically cattle-herding nomads, who nowadays practise two main confessions – Buddhism and Shamanism. (Photo by Ilya Naymushin/Reuters)