A team of ten acrobats form the shape of a racehorse crossing the winning post ridden by Stefanie Hofer to celebrate the upcoming Dubai Duty Free Shergar Cup at Ascot Racecourse on July 29, 2014 in Ascot, England. The Dubai Duty Free Shergar Cup is the only team-format raceday in the UK and takes place on 9th August. (Photo by Ian Gavan/Getty Images for Ascot Racecourse)

Members of a historical re-enactment group dressed as U.S. and Soviet Army soldiers take part in Elbe Day celebrations, in eastern German city of Torgau at the river Elbe, April 25, 2015. Elbe Day commemorates the encounter of the Allies 70 years ago, on the 25th of April 1945 when American and Soviet army units joined together on the destroyed bridge over the river Elbe. The photograph of the meaningful handshake made its way around the world and became a symbol of the near end of World War II in Europe. (Photo by Stefanie Loos/Reuters)

A prototype battery-powered plane, called Greased Lightning or GL-10 is pictured flying at NASA's Langley Research Center in this undated handout photo obtained by Reuters May 1, 2015. The plane, which has 10 engines and can take off like a helicopter and fly efficiently like an aircraft, is currently in the design and testing phase. (Photo by Reuters/NASA)

Chinese paramilitary guards monitoring passengers as they head to their train to travel to their hometowns for the “Spring Festival” or Lunar New Year at Nantong Railway Station in Jiangsu province, near Shanghai Travellers taking part in the world' s largest annual human migration must be home by January 27 to usher in the new year on January 28. (Photo by AFP Photo/Stringer)

Associated Press photographer Wong Maye-E tries to get her North Korean subjects to open up as much as is possible in an authoritarian country with no tolerance for dissent and great distrust of foreigners. She has taken dozens of portraits of North Koreans over the past three years, often after breaking the ice by taking photos with an instant camera and sharing them. Her question for everyone she photographs: What is your motto? Their answers reflect both their varied lives and the government that looms incessantly over all of them. (Photo by Wong Maye-E/AP Photo)

Young Japanese women dressed in colourful Kimonos take a photo of themselves as they gather for a ceremony marking the “Coming of Age Day” at the Toshimaen Amusement Park in Tokyo, Japan, 11 January 2016. The Coming of Age Day is the day to celebrate young people who turn 20 years old while the age of 20 is considered the beginning of adulthood and is the minimum legal age for voting, drinking and smoking in Japan. (Photo by Kiyoshi Ota/EPA)

Members of the Times Square Alliance snow clearing team take a photo on a snowbank at Times Square in the Manhattan borough of New York January 23, 2016. A winter storm dumped nearly 2 feet (58 cm) of snow on the suburbs of Washington, D.C., on Saturday before moving on to Philadelphia and New York, paralyzing road, rail and airline travel along the U.S. East Coast. (Photo by Shannon Stapleton/Reuters)

Runners wearing full solid-coloured bodysuits take part in a marathon in Tel Aviv, Israel February 26, 2016. Tens of thousands took part in the event, which saw streets closed off from Rokach Boulevard in the north to Jaffa’s Jerusalem Boulevard in the south. Other than the main 42-kilometer (26-mile) run, the day’s events also included a half-marathon route, several shorter circuits, a handcycle race for the handicapped and a mini-marathon for kids of a single kilometer (0.6 miles). (Photo by Amir Cohen/Reuters)