Passengers prepare to take part in the No Pants Subway Ride in Prague, Czech Republic, Sunday, January 8, 2017. The No Pants Subway Ride began in 2002 in New York as a stunt and has taken place in cities around the world since then. (Photo by Petr David Josek/AP Photo)

Star Wars actors on the Cantina set at Star Wars Celebration: The Ultimate Fan Experience held at the Anaheim Convention Center on Thursday, April 16, 2015, in Anaheim, Calif. (Photo by Richard Shotwell/Invision/AP 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)

Children guarded by Hungarian police play on the ground after being detained along with other migrants who illegally crossed from Serbia to Hungary near the village of Asotthalom, Hungary, September 16, 2015. (Photo by Dado Ruvic/Reuters)

A visitor looks at a creation by Russian artist Irina Nakhova presented at the Russia's pavilion during the 56th International Art Exhibition (Biennale d'Arte) titled “All the Worlds Futures” on May 5, 2015 in Venice. (Photo by Gabriel Bouys/AFP Photo)

The Blue Man Group performs on stage during a media preview ahead of their show in Singapore on March 31, 2016. Blue Man Group was started by three friends in New York in 1991 as a way to celebrate the human spirit through music, science, art and theater. (Photo by Roslan Rahman/AFP Photo)

A girl plays on a pile of discarded flowers outside a market, the day after the Diwali celebrations in Mumbai, India October 31, 2016. (Photo by Shailesh Andrade/Reuters)

Belgium. Rosalie, 9, goes to school in Brussels. “At my school we have separate toilets for girls and boys on every floor. My classroom is on the 3rd floor. We have 22 toilets, which are shared between 230 pupils and 20 adults. The teachers at school let us go to the toilet whenever we need to”. (Photo by Tim Dirven/WSUP/Panos)