U.S. soldiers from the 3rd Cavalry Regiment take part in an artillery exercise on forward operating base Gamberi in the Laghman province of Afghanistan December 24, 2014. (Photo by Lucas Jackson/Reuters)

People view Singpoli Group's inaugural Rose Parade float as it undergoes its finishing touches in Pasadena, California December 30, 2014. The 126th Rose Parade will take place on New Years Day in Pasadena. (Photo by Jonathan Alcorn/Reuters)

A light installation is seen on the facade on the banks of the Saone river to pay tribute to the victims of the Paris attacks in Lyon, France, December 8, 2015. (Photo by Robert Pratta/Reuters)

Miss Colombia 2015 Ariadna Gutierrez rehearses for the upcoming Miss Universe telecast while at Planet Hollywood Resort and Casino in Las Vegas, Nevada, December 12. 2015. (Photo by Darren Decker/Reuters/The Miss Universe Organization)

Policewomen take a picture inside a tunnel under the Chao Phraya river at a Mass Rapid Transit subway station in Bangkok, Thailand, December 14, 2015. (Photo by Athit Perawongmetha/Reuters)

Members of the ice swimming club “Berliner Seehunde” (Berlin Seals) take a dip in the Orankesee lake as part of their traditional Christmas swimming session in Berlin, Germany, December 25, 2015. (Photo by Hannibal Hanschke/Reuters)

Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)

A woman takes part in a traditional horse parade through the streets of San Jose, Costa Rica December 26, 2015. Thousands of riders participated in the parade, which is part of annual year-end festivities. (Photo by Juan Carlos Ulate/Reuters)