F/A-18 fighter jet takes off from the USS Harry S. Truman aircraft carrier in the eastern Mediterranean Sea June 13, 2016. (Photo by Baz Ratner/Reuters)

Revellers attend the Play Time 2016 music festival on the outskirts of Ulaanbaatar, Mongolia, June 26, 2016. (Photo by Jason Lee/Reuters)

2016 Rio Olympics, Artistic Gymnastics, Preliminary, Women's Qualification, Subdivisions, Rio Olympic Arena, Rio de Janeiro, Brazil on August 7, 2016. Ruby Harrold (GBR) of United Kingdom (341) applies lipstick for Elissa Downie (GBR) of United Kingdom (centre R) during the women's qualifications. (Photo by Damir Sagolj/Reuters)

Wang Zhengqing, a 74 year old pneumoconiosis patient, smokes his pipe at Yangjia Hospital in Wuyi County, Zhejiang Province, China October 19, 2015. Former miner Wang was diagnosed with the disease, which is caused by dust inhalation, when he was 24 and has lived at Yangjia Hospital for ten years. (Photo by Damir Sagolj/Reuters)

A demonstrator dressed as Santa Claus holds up a flag as a riot police vehicle releases a jet of water during a protest against the private system of pension fund administrators in Santiago, Chile, December 10, 2015. The flag reads “Classist Workers Union”. (Photo by Ivan Alvarado/Reuters)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Comic Con fans in costume arrive for the 2nd day of the 2016 New York Comic Con at the Jacob Javits Center on October 7, 2016. The four- day event which runs October 6-9 is the largest pop culture event on the East Coast. (Photo by Timothy A. Clary/AFP Photo)

Wakhi nomad women milk yaks in Wakhan, Afghanistan. About 12,000 villagers live at an altitude of 4,500 metres in the harsh, desolate terrain. The Wakhi people live a simple, relaxed life with their livestock. (Photo by Eric Lafforgue/Barcroft Images)