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)

A model presents a creation by Paradizia during Colombiamoda fashion event in Medellin, Colombia, July 29, 2015. (Photo by Fredy Builes/Reuters)

A chicken seller carries his chickens on his head in the market in Peshawar, Pakistan, August 20, 2015. (Photo by Khuram Parvez/Reuters)

A man enters an adult amusement establishment in Shinjuku's nightlife district of Kabukicho in Tokyo, August 27, 2015. (Photo by Thomas Peter/Reuters)

A couple who did not give their names walk in downtown Havana, February 2, 2015. (Photo by Alexandre Meneghini/Reuters)

The moon rises behind the skyline and financial district in Toronto, November 25, 2015. (Photo by Mark Blinch/Reuters)

Dragon boat racers prepare for the fancy dress race on July 5, 2015 in Hong Kong, Hong Kong. The Hong Kong Dragon Boat Carnival will be staged from 3 July 2015 (Friday) to 5 July 2015 (Sunday). The carnival featured two key programmes: the CCB (Asia) Hong Kong International Dragon Boat Races in Victoria Harbour and the San Miguel BeerFest at the UC Centenary Garden in East Tsim Sha Tsui. (Photo by Taylor Weidman/Getty Images for Hong Kong Images)