An Afghan man works at a traditional yarn factory in Heart province, Afghanistan July 28, 2015. (Photo by Mohammad Shoib/Reuters)

A dog jumps over an obstacle during the International Agility Riga Cup competition in Riga, Latvia, August 15, 2015. (Photo by Ints Kalnins/Reuters)

Revellers watch as police officers dance in the street at the Notting Hill Carnival in west London, August 30, 2015. (Photo by Toby Melville/Reuters)

A man rows a boat on the Dal Lake as a woman holds an umbrella during snowfall in Srinagar February 19, 2015. (Photo by Danish Ismail/Reuters)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

Ukrainian Air Force officers attend a graduation ceremony at the National University of Defence of Ukraine in Kiev, April 24, 2015. (Photo by Gleb Garanich/Reuters)

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)