A trainer tries to convince a dog to jump over an obstacle during the Dog Olympic Games in Rio de Janeiro, Brazil, Sunday, September 18, 2016. Owner of the dog park and organizer of the animal event Marco Antonio Toto says his goal is to socialize humans and their pets while celebrating sports. (Photo by Silvia Izquierdo/AP Photo)

A participant of the sled dogs race in action with the dogs in Stroehen (Lower Saxony), Germany, 18 October 2015. It is the first round of the North German Championship. (Photo by Peter Steffen/EPA)

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)

Iranian demonstrators burn an Israeli flag during a rally marking al-Quds (Jerusalem) Day in Tehran July 10, 2015. (Photo by Reuters/Stringer/TIMA)

A demonstrator jumps from a vehicle of the Organisation for Security and Co-operation in Europe (OSCE) during a protest to demand what protesters say is true information from the OSCE about the shelling in Donetsk, Ukraine (since April 2014, the city is the administrative centre of the Donetsk People's Republic), July 23, 2015. The graffiti reads, “Stop moronic war!”. (Photo by Alexander Ermochenko/Reuters)

In this photo provided by Mickey Nuttall, members of an international team of skydivers join hands, flying head-down to build their world record skydiving formation, Friday, July 31, 2015, over Ottawa, Ill. (Photo by Jason Peters via AP Photo)

A model wears a creation for Vivienne Westwood's Spring-Summer 2016 ready-to-wear fashion collection, presented during the Paris Fashion Week in Paris, Saturday October 3, 2015. (Photo by Francois Mori/AP Photo)