German fan Didi Senft known as El Diablo cheers as the pack rides past during the 234.5 km seventh stage of the 101st edition of the Tour de France cycling race on July 11, 2014 between Epernay and Nancy, northeastern France. (Photo by Lionel Bonaventure/AFP Photo)

Singer Madonna performs during her concert at the AccorHotels Arena in Paris, France, December 9, 2015, on her Rebel Heart Tour. (Photo by Benoit Tessier/Reuters)

People use snowshoes during a tour of the Great Kemeri Bog, Latvia, October 17, 2015. The Kemeri bog is more than 8,000 years old and is one of the largest dry moss swamps in the Baltics. A more than decade-long joint restoration of the bog by the European Union and the Latvian government helped the bog recover its high moss marshes, damp black alder forests, floodplain meadows and seaside lakes – features now considered rare in Europe due to industrialisation. (Photo by Ints Kalnins/Reuters)

In this November 28, 1966 file photo, one of the 10 beagles involved in the first test of the Veterans Administration Hospital in East Orange, N.J. smokes a cigarette through a machine linked to its windpipe by a plastic tube to test any link between smoking and emphysema. (Photo by AP Photo)

A photographer has taken an explosive set of images by igniting gasoline in midair. Rob Prideaux, 45, photographs fire and smoke and then creates patterns from it. The San Francisco-based artist captures the fire in the split second its visible by using highly arcane methods. Rob's Smoke and Fire series is his quest “to shape one of the more uncontrollable phenomena in nature”. (Photo by Rob Prideaux)

Keith Richards, Mick Jagger, Ron Wood of the Rolling Stones perform during their "14 on Fire" show at Waldbuehne in Berlin, June 10, 2014. REUTERS/Thomas Peter

The Royal Castle is seen a veil of heavy winter smog in Budapest, Hungary on January 30, 2017. (Photo by Laszlo Balogh/Reuters)