A student aims a stick of wood at Bolivarian National Police officers during clashes outside the Central University in Caracas, Venezuela, Thursday, June 9, 2016. Students had planned to march from Venezuela's top university to elections headquarters, but hundreds of police in riot gear blocked the way. Students covered their faces with Venezuelan flags and threw bottles, stones and sticks while police lobbed tear gas. (Photo by Fernando Llano/AP Photo)

A man poses for a photograph in front of a mural of Democrat US presidential nominee Hillary Clinton clad in a swimsuit bearing the colours of the US flag in West Footscray in Melbourne on July 30, 2016. An Australian mural of US presidential nominee Hillary Clinton in a revealing, stars and stripes swimsuit may be taken down, after it has reportedly been deemed offensive. (Photo by Paul Crock/AFP Photo)

Nigel Lamb from Great Britain, left, leading Juan Velarde of Spain, centre, and Martin Šonka of Czech Republic in the FAI Red Bull air race, Isle of Wight, UK on August 9, 2016. (Photo by Joerg Mitter/Red Bull/Global New/PA Wire)

Lulu, her Playa name, falls into a foam pit as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. September 1, 2016. (Photo by Jim Urquhart/Reuters)

Cuban-American artist Jorge Rodriguez-Gerada's six-acre sand and soil “facescape” stretches across the JFK Hockey Field on the north side of the Reflecting Pool along the National Mall October 1, 2014 in Washington, DC. Titled “Out of Many, One” and composed of 2,500 tons of sand, 800 tons of top soil and eight miles of string, the piece is the artist's interpreative blending of 30 different men's faces. Rodriguez-Gereda used high-precision global positioning satellites to place 10,000 wood pegs as waypoints for the giant face. The piece will be open to the public beginning October 4 and will eventually be tilled back into the earth. (Photo by Chip Somodevilla/Getty Images)

Civilians are led by members of pro-Russian self-defence units as they run outside a military base during an assault in the Crimean town of Belbek near Sevastopol March 22, 2014. Russian troops forced their way into a Ukrainian airbase in Crimea with armored vehicles, automatic fire and stun grenades on Saturday, injuring a Ukrainian serviceman and detaining the base's commander for talks. (Photo by Vasily Fedosenko/Reuters)

A Model styled by a participant waits to be judged by the jury during the contest “Day style” of the OMC Hairworld World Cup on May 4, 2014 in Frankfurt am Main, Germany. (Photo by Thomas Lohnes/Getty Images)

A woman tries to protect her daughter as refugees scuffle with the Greek police in their effort to reach the borderline with Macedonia, near the Greek village of Idomeni, Sunday, November 22, 2015. Over 1,000 migrants gathered in the Greek town Idomeni protested Saturday against the decision by Macedonian authorities across the border to turn away migrants who are not from war zones such as Syria, Afghanistan and Iraq. (Photo by Giannis Papanikos/AP Photo)