Libyan forces allied with the U.N.-backed government fire a shell at Islamic State fighters' positions in Sirte, Libya August 15, 2016. (Photo by Ismail Zitouny/Reuters)

Valentin Arias Delgado and Diana Franco Durango, from Colombia, perform their routine at the Stage style Tango World Championship, in Buenos Aires, Argentina, August 31, 2016. (Photo by Enrique Marcarian/Reuters)

Dayane Mello attends the photocall for the television miniseries “The Young Pope” at the 73rd Venice Film Festival in Venice, Italy, September 3, 2016. (Photo by Alessandro Bianchi/Reuters)

A towel with a print of the Nigerian naira is displayed for sale at a street market in the central business district in Nigeria's commercial capital Lagos February 4, 2016. (Photo by Akintunde Akinleye/Reuters)

African migrants stranded in Costa Rica walk near garbage on the Inter-American highway at the border between Costa Rica and Nicaragua, in Penas Blancas, Costa Rica, September 8, 2016. (Photo by Juan Carlos Ulate/Reuters)

Miss Utah Krissia Beatty competes in the swimsuit competition during the first night of preliminaries of Miss America at Boardwalk Hall in Atlantic City, New Jersey, September 8, 2015. (Photo by Mark Makela/Reuters)

A dog catches a frisbee during a dog frisbee competition in Moscow, September 13, 2015. Dogs and their owners took part in a variety of distance and accuracy tests during the competition to check their frisbee skills. (Photo by Sergei Karpukhin/Reuters)

Members of Saudi security forces take part in a military parade in preparation for the annual Haj pilgrimage in the holy city of Mecca September 17, 2015. (Photo by Ahmad Masood/Reuters)