A competitor participates in the Tough Mudder challenge near Henley-on-Thames in southern England May 2, 2015. (Photo by Eddie Keogh/Reuters)

A helicopter drops water over a wildfire as a firefighter works to contain it in Benahavis, southern Spain, May 19, 2015. (Photo by Jon Nazca/Reuters)

A participant smiles at the annual Christopher Street Day parade on Kurfuerstendamm in Berlin, Germany, June 27, 2015. (Photo by Fabrizio Bensch/Reuters)

A child plays with a soap bubble on the city hall plaza on March 14, 2015 in Paris. (Photo by Dominique Faget/AFP Photo)

A visitor tries a baccarat game at the Global Gaming Expo (G2E) Asia in Macau, China May 19, 2015. (Photo by Bobby Yip/Reuters)

A man pulls a cart with collapsed cardboard boxes past boutiques in the Sinchon district in Seoul, May 5, 2015. (Photo by Thomas Peter/Reuters)

Revellers from Russia parade during the Aoussou Carnival in Sousse, Tunisia July 26, 2015. (Photo by Anis Mili/Reuters)

Models wear creations by brand Leonisa during Colombiamoda fashion event in Medellin, Colombia, July 28, 2015. (Photo by Fredy Builes/Reuters)