A girl looks at other children practicing on a boxing ring during an exercise session at a boxing school, in the Mare favela of Rio de Janeiro, Brazil, June 2, 2016. For many young residents the Luta Pela Paz (Fight For Peace) academy offers a glimpse of an alternative: a chance to build discipline and self-esteem through boxing and martial arts. (Photo by Nacho Doce/Reuters)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

A barn painted with the U.S. flag is seen in the snow covered field in Kanawha, Iowa, United States, January 16, 2016. Iowa will be the first state to hold its primary, with both Democratic and Republican events being held February 1, 2016. (Photo by Jim Young/Reuters)

Mermaid Hales Parcells geets children as she performs at the Virginia Aquarium in Virginia Beach, Va., Monday, April 3, 2017. The Aquarium presents a mermaid show one night each week during the month of April. (Photo by Steve Helber/AP Photo)

Residents cross over an improvised bridge after a landslide sent mud and water crashing onto homes close to the municipality of Salgar in Antioquia department, Colombia May 19, 2015. A landslide sent mud and water crashing onto homes in a town in Colombia's northwest mountains on Monday, killing at least 50 people and injuring dozens, officials said. (Photo by Jose Miguel Gomez/Reuters)

An Iraqi man cooks traditional Masgouf fish on a barbecue for sale in the Karada market July 02, 2014. Masgouf, one of the national dishes of Iraq is a grilled carp seasoned with olive oil, rock salt, tamarind and ground turmeric. (Photo by Scott Nelson for the Washington Post)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

Brittnai of El Paso, Texas, USA, performs in the Professional Division Competition during the 5th Annual US Pole Dance Championship on April 1, 2017 at the Symphony Space Theater in New York City. (Photo by Timothy A. Clary/AFP Photo)