An armed man gestures in front of the police headquarters in Slaviansk, April 12, 2014. At least 20 armed militants wearing mismatched camouflage outfits took over the police and security services headquarters in the eastern city of Slaviansk seizing hundreds of handguns. (Photo by Gleb Garanich/Reuters)

Colleen Kelley, of Iowa City, Iowa, fixes the hat on her dog Bruce during judging at the 35th annual Drake Relays Beautiful Bulldog Contest, Monday, April 21, 2014, in Des Moines, Iowa. The pageant kicks off the Drake Relays festivities at Drake University where a bulldog is the mascot. (Photo by Charlie Neibergall/AP Photo)

A white Bengal tiger cub plays with its mother in a zoo in the Siberian city of Novosibirsk, about 2,800 kilometers (1,750 miles) east of Moscow, Russia, Tuesday, April 21, 2015. Two blue-eyed Bengal tiger cubs were born in March to a couple of white tigers at Novosibirsk zoo. (Photo by Ilnar Salakhiev/AP Photo)

Sam Warren climbs in to a prototype combat vehicle during the PrepperCon expo Friday, April 24, 2015, in Sandy, Utah. Hundreds of survivalists and “preppers” are gathering in the Salt Lake City suburb of Sandy for the first annual PrepperCon, featuring demonstrations of underground bunkers, food storage, and armored vehicles. (Photo by Rick Bowmer/AP Photo)

Guests arrive for the opening ceremony of the 23rd Life Ball in Vienna May 16, 2015. Life Ball is Europe's largest annual AIDS charity event and takes place in Vienna's city hall. The Life Ball is a charity gala to raise money for people living with HIV and AIDS. (Photo by Leonhard Foeger/Reuters)

In this photograph taken on June 28, 2015, a hiker in Hong Kong takes a picture of the city from a walking trail. The southern Chinese territory is crisscrossed by more than 180 miles of designated hiking trails. (Photo by Alex Ogle/AFP Photo)

Indian commuters wade through floodwaters during the continuous rain shower in Calcutta, India, July 10, 2015. A monsoon shower hit the city and disrupted daily life. The Indian monsoon, takes place between May and September. (Photo by Piyal Adhikary/EPA)

A woman looks at La Paz city from the Jacha Qhatu cable car station in El Alto, July 23, 2015. Bolivia already has the largest urban cable car system in the world. Now the booming country is tripling the size of the network and will soon have nine lines whizzing above the administrative capital of La Paz. (Photo by David Mercado/Reuters)