A man from Dinka tribe holds his AK-47 rifle in front of cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. (Photo by Goran Tomasevic/Reuters)

Fans cheer in the stands ahead of the CFL's 102nd Grey Cup football championship between the Calgary Stampeders and the Hamilton Tiger Cats in Vancouver, British Columbia, November 30, 2014. (Photo by Todd Korol/Reuters)

Contestants of a tourism beauty pageant balance eggs on their collarbones as they cruise along the Yellow River in Jiyuan, Henan province, China, June 22, 2015. The contestants believe that if they are slim enough, their collarbones will allow them to balance the eggs securely on their bodies. (Photo by Reuters/Stringer)

Street fighting in Berlin between Government troops and Spartacists, during the Spartacist uprising which followed Germany's defeat in World War I. (Photo by Keystone/Getty Images). 1919

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

Belarusian Sergei Selekh plays with his 6-month-old tamed wolves on the outskirts of the village of Gaina, 45 kilometers (28 miles) north of Belarus capital Minsk, Wednesday, December 31, 2014. Selekh owns a farmstead, where sheep, wolves and an ethnographic museum serve as entertainment for guests. (Photo by Sergei Grits/AP Photo)

A woman takes her souvenir picture with a white fox in front of ice sculptures illuminated by coloured lights during the opening day of the 31st Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province, January 5, 2015. The annual Ice and Snow Festival, organized by China National Tourism Administration and local governments, kicked off on Monday in Harbin, one of the coldest cities in China. (Photo by Kim Kyung-Hoon/Reuters)

Eighty one-year-old Sakon Haba (L) wearing loin cloth walks past a police station after he bathed in ice-cold water at the Teppozu Inari shrine in Tokyo January 11, 2015. According to organizers, about 100 participants took part in the Shinto ceremony to purify their souls and wish for good health in the new year. (Photo by Toru Hanai/Reuters)