A couple sunbath on the beach in Ostrowo, northern Poland, July 20, 2015. Picture taken July 20, 2015. (Photo by Kacper Pempel/Reuters)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

A Polisario fighter sits on a rock at a forward base on the outskirts of Tifariti, Western Sahara, September 9, 2016. At a rocky outpost in Western Sahara, a new generation of soldiers who have never known war are mobilising as tensions resurface in one of Africa's oldest disputes after a quarter century of uneasy peace. (Photo by Zohra Bensemra/Reuters)

A model walks the runway during the Versace show as part of Paris Fashion Week Haute Couture Spring/Summer 2015 on January 25, 2015 in Paris, France. (Photo by Pascal Le Segretain/Getty Images)

Models prepare backstage ahead of the Strateas.Carlucci show at Mercedes-Benz Fashion Week Australia 2015 at Carriageworks on April 13, 2015 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)

Models backstage ahead of the St George New Generation show at Mercedes-Benz Fashion Week Australia 2015 at Carriageworks on April 16, 2015 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

Promotional staff dressed in outfits of animation characters use a mobile phone at the Global Mobile Internet Conference (GMIC) 2015 in Beijing, China, April 28, 2015. (Photo by Kim Kyung-Hoon/Reuters)

Models promote the game “Diamond Dogs” during the Gamescom 2015 fair in Cologne, Germany August 5, 2015. Hundreds of thousands of visitors will enjoy one of the world's largest computer and video game events until Sunday. (Photo by Kai Pfaffenbach/Reuters)