A U.S. Army soldier with the 10th Special Forces Group and his military working dog jump off the ramp of a CH-47 Chinook helicopter from the 160th Special Operations Aviation Regiment during water training over the Gulf of Mexico as part of exercise Emerald Warrior 2011 on March 1, 2011. (Photo by Tech. Sgt. Manuel J. Martinez/U.S. Air Force)

Russians play accordions as they walk near the building of the Federal Security Service (FSB, Soviet KGB successor) in Lubyanskaya Square to mark May Day in Moscow, Russia, Sunday, May 1, 2016. As in Soviet times, about one hundred thousand of cheerful workers paraded across Red Square despite a chilly rain, but instead of red flags with the Communist hammer and sickle, they waved the blue flags of the dominant Kremlin party and the Russian tricolor. (Photo by Alexander Zemlianichenko/AP Photo)

A Tibetan Buddhist nun spins a prayer wheel in sub zero temperatures at a Buddhist laymen lodge where thousands of people gather for daily chanting session during the Utmost Bliss Dharma Assembly, the last of the four Dharma assemblies at Larung Wuming Buddhist Institute in remote Sertar county, Garze Tibetan Autonomous Prefecture, Sichuan province, China November 1, 2015. (Photo by Damir Sagolj/Reuters)

Nubian women sell traditional handicrafts at the Nubian Gharb Suheil village, near Aswan south of Egypt, October 1, 2015. For half a century, Egypt's Nubians have patiently lobbied the government in Cairo for a return to their homelands on the banks of the upper Nile, desperate to reclaim territory their ancestors first cultivated 3,000 years ago. (Photo by Mohamed Abd El Ghany/Reuters)

Men wearing masks and dressed as military members take part in a festival honouring San Silvestre, in the town of Catarina, Nicaragua January 1, 2016. The placard reads, “I'm not afraid, young people off the streets, Ortega you sell our country”, in reference Nicaragua's President Daniel Ortega. (Photo by Oswaldo Rivas/Reuters)

A worker sweeps leaves below a historic spirit still at Suntory Holdings' Yamazaki Distillery in Shimamoto town, Osaka prefecture, near Kyoto, December 1, 2014. Nestled at the foot of wooded hills near the ancient Japanese capital of Kyoto, the Yamazaki whisky distillery feels a long way from the northerly glens of Scotch's spiritual home. Despite its unlikely birthplace, last month Yamazaki's Single Malt Sherry Cask 2013 trumped more than a thousand challengers to be named the world's best whisky by leading critic Jim Murray in his Whisky Bible 2015. (Photo by Thomas Peter/Reuters)

Autos sit on top of each other in a washed out section of Dog Track Road in the Millview community as Gulf Coast residents continue cleaning up from damage caused by torrential rains in Pensacola, Fla., Thursday, May 1, 2014. The National Weather Service, estimated 15-20 inches of rain has fallen in the Pensacola area in the past 2 days. (Photo by G. M. Andrews/AP Photo)

Tourists take a “selfie” as demonstrators burn a trash container during a May Day rally in Barcelona, Spain, on May 1, 2014. Tens of thousands of workers marked May Day in European cities with a mix of anger and gloom over austerity measures imposed by leaders trying to contain the eurozone's intractable debt crisis. (Photo by Manu Fernandez/Associated Press)