People clash with Venezuelan National Guards as they try to cross the border to Colombia over the Francisco de Paula Santander international bridge in Urena, Venezuela December 18, 2016. (Photo by Carlos Eduardo Ramirez/Reuters)

A participant wearing Kokoshnik, the Russian traditional headwear, walks out of the water during winter swimming festival in the town of Podolsk, south of Moscow, Russia January 5, 2017. (Photo by Maxim Shemetov/Reuters)

A combination picture shows Will Adam, 14, snowboarding down a street on Beacon Hill during a large winter blizzard in Boston, Massachusetts, United States January 27, 2015 (top), and a woman looking at her phone as she walks down the same street June 13, 2015. Outdoor scenes in Boston show local residents enjoying balmy weather amid lush greenery as the summer solstice approaches on 21 June. The very same locations suffered heavy snowstorms last winter, with snow ploughs, skiers and snowboarders battling the drifts. Boston got 275.8 cm of snow over the winter, the most since 1872, when records began. A few months after the snowstorms, Brian Snyder revisited the same places and shot pictures at exactly the same locations. (Photo by Brian Snyder/Reuters)

An Iranian woman gestures as she celebrates in the streets following a nuclear deal with major powers, in Tehran July 14, 2015. Overcoming decades of hostility, Iran, the United States, and five other world powers struck a historic accord Tuesday to check Tehran's nuclear efforts short of building a bomb. The agreement could give Iran access to billions in frozen assets and oil revenue, stave off more U.S. military action in the Middle East and reshape the tumultuous region. (Photo by Reuters/TIMA)

“Sniff out the Appenzell Cheese”. Alexander Hunter, 30, of Greenwich, Conn., took this photo in Appenzell, Switzerland, in September 2014. (Photo by Alexander Hunter)

A boy walks with toy guns as people ride an APC during a military show at the Finnish Gulf coast in St.Petersburg, Russia, Saturday, September 5, 2015. (Photo by Dmitry Lovetsky/AP Photo)

A visitor visit the “12 Labors of Putin” art exhibition on October 6, 2014 marking the 60th birthday of Russia's President Vladimir Putin at the design workshop in Moscow. (Photo by Vasily Maximov/AFP Photo)

A Brussels Airlines aircraft prepares for landing in Cointrin airport during sunrise over the Mont Blanc in Geneva December 1, 2011. (Photo by Denis Balibouse/Reuters)