Participants ride horses, hold spears and wear historic armoured suits of the Middle Ages as they compete during the Saint George international knight tournament in Moscow, Russia, May 3, 2015. (Photo by Maxim Zmeyev/Reuters)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

A woman is consoled by her relative as she mourns after seeing her house getting burned during a fire that broke out in one of the houses and got spread in more adjoining houses, in a residential locality in Srinagar, November 21, 2016. (Photo by Danish Ismail/Reuters)

Crowds watch surfers as the first big swell of the year arrives in Nazaré, Portugal on October 28, 2015. (Photo by Pedro Miranda/Demotix/Corbis)

Villagers look on as Mount Sinabung volcano spews thick volcanic ash, as seen from Beganding village in Karo, North Sumatra province, on May 19, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

Britain Horse Racing, Royal Ascot, Ascot Racecourse on June 17, 2016. Chelsea pensioners with a racegoer posing between them. (Photo by Toby Melville/Reuters/Livepic)

A girl with Russian national flags painted on her cheeks takes part in celebrations marking the first anniversary of Russia's annexation of Crimea, in central Simferopol March 16, 2015. Russia marks one year anniversary of annexation of Ukraine's Crimea peninsula this week. (Photo by Maxim Shemetov/Reuters)

Dancers prepare before a performance in the backstage area of the Buick exhibition during the “Auto China 2014” Beijing International Automotive Exhibition in Beijing on April 21, 2014. Leading automakers have gathered in Beijing for the kickoff of China's biggest car show, but lackluster growth and environmental restrictions in the world's largest car market have thrown uncertainty into the mix. (Photo by AFP Photo)