A member of a local swimming club holds a Russian national flag as he dives in at the start of a 24-hour swimming marathon near the western Siberian city of Barnaul March 29, 2014. Thirty members of the club will swim in turn during the event, held to mark Crimea becoming part of Russia, local media reported. (Photo by Andrei Kasprishin/Reuters)

A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

A Syrian rebel walks past Sham 2, a homemade armored vehicle, in Bishqatin, Syria, on December 8, 2012. From a distance it looks rather like a big rusty metal box but closer inspection reveals a homemade armored vehicle waiting to be deployed. Sham II, named after ancient Syria, is built from the chassis of a car and touted by rebels as “100 percent made in Syria”. (Photo by Herve Bar/AFP Photo)

Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

A fan dressed as “Loki” poses before the European premiere of “Avengers: Age of Ultron” at Westfield shopping centre in Shepherds Bush, London April 21, 2015. (Photo by Stefan Wermuth/Reuters)

A model's make up picture is stuck to a mirror backstage during the Autumn/Winter Madrid's Mercedes Benz Fashion Week, in Madrid, Wednesday, February 1, 2012. (Photo by Daniel Ochoa de Olza/AP Photo)

North Korean soldiers wave along the Yalu River, near the North Korean town of Sinuiju, opposite to the Chinese border city of Dandong October 7, 2014. (Photo by Jacky Chen/Reuters)