Pakistani female police commandos attend a training session in Nowshera, near Peshawar Pakistan, Wednesday, February 11, 2015. Authorities formed a Special Combat Unit after Taliban militants stormed a Peshawar school on Dec. 16, 2014 and massacred 150 children and teachers. (Photo by Mohammad Sajjad/AP Photo)

A visitor looks at pictures of French photographer Jacques-Henri Lartigue (1894-1986), on July 1, 2013 during the 44thd annual Rencontres d'Arles photography festival in Arles, southern France. The event runs until September 22. (Photo by Boris Horvat/AFP Photo)

Employees of a food stand take pictures of Titan, a robot created by England Cyberstein Robots, performing at the Danilovsly market in downtown of Moscow, Russia, 12 May 2014. Titan visited to Moscow to attend “Bal Robotov”, an interactive exhibition of the most recent advances in robotics which will be opened on 15 May in Artplay Moscow exhibition center. Titan worked alongside superstars including Will.i.am, Rihanna, Will Smith and Jackie Chan. (Photo by Sergei Ilnitsky/EPA)

A man runs after he tried to put himself on fire during a protest at a makeshift camp at the Greek-Macedonian border near the village of Idomeni on March 22, 2016. Greece will not be able to start sending refugees back to Turkey from March 20, 2016, the government said, as the country struggles to implement a key deal aimed at easing Europe's migrant crisis. The numbers are daunting: officials said as of Saturday there were 47,500 migrants in Greece, including 8,200 on the islands and 10,500 massed at the Idomeni camp on the Macedonian border. (Photo by Andrej Isakovic/AFP Photo)

A young Chinese girl kicks during a kung-fu class at Ritan Park on June 11, 2016 in Beijing, China. Ritan, meaning “sun altar”, is among the oldest parks in Beijing, built in the early 1500s during the Ming dynasty for the emperor to make sacrifices to the sun. (Photo by Kevin Frayer/Getty Images)

Brazilian navy soldiers watch a woman as they patrol the area at the Copacabana Beach before carnival festivities in Rio de Janeiro, Brazil February 14, 2017. (Photo by Sergio Moraes/Reuters)

A woman takes her souvenir picture with a white fox in front of ice sculptures illuminated by coloured lights during the opening day of the 31st Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province, January 5, 2015. The annual Ice and Snow Festival, organized by China National Tourism Administration and local governments, kicked off on Monday in Harbin, one of the coldest cities in China. (Photo by Kim Kyung-Hoon/Reuters)

Mario Huettenhofer, chief of the German company 3D Fab, presents his own face as 3d print during the international fairs FabCon 3.D and Rapid.Tech in Erfurt, Germany, Thursday, May 15, 2014. 130 exhibitors from all over the world present the entire world of 3D printing. The trade fairs are accompanied by specialist programs featuring 80 scientists, practitioners and trend analysts from ten countries, who will explain the latest findings, trends and applications for additive processes in industry and for 3D printing in the private sector to newcomers, experts and consumers alike. (Photo by Jens Meyer/AP Photo)