Teenagers on roller skates hold on to each other as they are pulled by a vintage car to move along a street in Havana, Cuba March 19, 2016. (Photo by Ivan Alvarado/Reuters)

A man poses for a photograph in front of a mural of Democrat US presidential nominee Hillary Clinton clad in a swimsuit bearing the colours of the US flag in West Footscray in Melbourne on July 30, 2016. An Australian mural of US presidential nominee Hillary Clinton in a revealing, stars and stripes swimsuit may be taken down, after it has reportedly been deemed offensive. (Photo by Paul Crock/AFP Photo)

Kurdish guard women from the civilian protection unit which supports the Democratic Forces of Syria, cheer near the Syrian town of al Houl in Hasaka province, after the Democratic Forces of Syria took control of the area, November 14, 2015. A U.S.-backed Syrian rebel alliance on Friday captured the town of al Houl in Hasaka province, which had been held by Islamic State militants, a spokesman for the Kurdish fighters, part of the grouping, said. It was the first significant advance against IS by the Democratic Forces of Syria, which was formed last month. (Photo by Rodi Said/Reuters)

A woman looks at a swimmer getting herself warm after the annual Christmas winter swimming competition in the Vltava river in Prague December 26, 2014. (Photo by David W. Cerny/Reuters)

Friends of Li Guojun drive a homemade tank-shaped vehicle in Kangping county, China. Li, a farmer who is a fan of tanks, spent six months with help from his friends to construct the almost 20-foot vehicle which weighs 2.5 tons. (Photo by Sheng Li/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)

Emma the Maltese's fur blows in the wind as she rides in her owner's purse on 5th Avenue at Central Park in New York December 2, 2014. (Photo by Carlo Allegri/Reuters)

“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)