A woman tour skates on the frozen lake of Orlangen, south of Stockholm, Sweden, on December 23, 2016. Tour skating is recreational long distance ice skating on natural ice particularly popular in the Nordic countries. (Photo by Tobias Roestlund/AFP Photo/TT News Agency)

A visitor stands in the exhibition “I Am A Drop In The Ocean” dedicated to the artistic and visual expressions of the protests that shook the Ukraine from November 2013 until February 2014 at the Kuenstlerhaus gallery in Vienna, Austria, Thursday, April 10, 2014. The exhibition opens its doors from April 11 until May 23, 2014. (Photo by Ronald Zak/AP Photo)

A stuntman performs in a car at the “Well of Death” at an exhibition in Srinagar, India, Friday, May 23, 2014. In the Well of Death, stunt drivers on motorbikes and cars drive in circles around the vertical walls of the well-shaped construction. (Photo by Dar Yasin/AP Photo)

British tourists snap a cheeky selfie with a monkey at the Ubud Monkey Forest in Bali, Indonesia, August 4, 2015. George Benton, 22, from Paignton, Devon was visiting the Sacred Monkey Forest Sanctuary in Ubud, Bali whilst traveling with his girlfriend Chloe when the couple snapped a surprise shot with Balinese long-tailed monkey using a “selfie stick”. “We couldn't believe our luck when we looked back at the photos, he looked straight into the camera!” said George, who went on to reward the cheeky chap with a banana for giving the couple such a memorable photo. (Photo by George Benton/Splash News)

Bikini-clad women ski as they are led by a car during a performance on the frozen Yenisei River outside Krasnoyarsk, Siberia, Russia, March 20, 2016. The performance, entitled “Siberian Spring's Strings” and created with the participation of artist Vasily Slonov, marked the day of spring equinox (vernal equinox), according to organizers. (Photo by Ilya Naymushin/Reuters)

Female pilot Anna climbs out the cockpit of Japanese electronics company Suidobashi Heavy Industry's newly unveiled robot “Kuratas” at the Wonder Festival in Chiba, suburban Tokyo on July 29, 2012. The “Kuratas” robot, which will go on sale with a price tag of one million USD, measures four meters in height, weighs four tons and has four wheeled legs that can either be controlled remotely through the 3G network or by a human seated within the cockpit. (Photo by Yoshikazu Tsuno/AFP Photo)

A prisoner from the Pedrinhas prison is carried to receive medical help after he was injured during a fight between rival gangs inside the jail, in Sao Luiz, capital of Maranhao state, January 8, 2014. The recent posting on a major Brazilian news website of a video filmed last December 17 by Pedrinhas prisoners of the decapitated and tortured bodies of rival inmates inside the jail has highlighted some of the problems present in the country's prison system which houses nearly twice as many prisoners as its capacity, according to official statistics. (Photo by Douglas Cunha/Reuters/O Estado do Maranhão)

A man is silhouetted as he stands on a walkway in the sky lobby at the Chancellery, the seat of German Chancellor Angela Merkel (not pictured) in Berlin, May 7, 2014. (Photo by Thomas Peter/Reuters)