North Korean youngsters sing and play accordions to entertain foreign visitors including United Nations Secretary General Kurt Waldheim, who visited Pyongyang, May 4, 1979. Visitors report music education in North Korea begins at an early age and is taken seriously by children and adults. (Photo by Peter Arnett/AP Photo)

Afghan children play on the remains of a Soviet-era armored personnel carrier on the outskirts of Jalalabad on February 15, 2016. Soviet troops withdrew from Afghanistan on February 15, 1989, after ten years of fighting against Mujahidin militiamen. (Photo by Noorullah Shirzada/AFP Photo)

Mariam, a 9-year-old girl, carries her brother as she stands with other children at an underground ancient cemetery in Jabal al-Zawiya in the southern countryside of Idlib November 26, 2014. Residents are using ancient caves and cemeteries as underground shelters to hide in during shelling from forces loyal to President Bashar al-Assad. Picture taken November 26, 2014. (Photo by Khalil Ashawi/Reuters)

Participants dressed as Santa Claus gather shortly before the 4th annual Michendorf Santa Run (Michendorfer Nikolauslauf) on December 9, 2012 in Michendorf, Germany. Over 800 people took part in this year's races that included children's and adults' races. (Photo by Sean Gallup)

In this March 18, 2015 photo, a boy rides a mechanical bull for children at the Texcoco Fair on the outskirts of Mexico City. In Mexico, these types of fairs date back to Spanish colonial times, and in some smaller communities they are organized around the feast days of Roman Catholic saints. (Photo by Eduardo Verdugo/AP Photo)

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)

People take part in the Cupid's Undie Run in the Manhattan borough of New York February 7, 2015. The run, held to raise funds to combat children's tumors, sees runners in their underwear partying and running along the West Side Highway. (Photo by Carlo Allegri/Reuters)

Kashmiri children play with snow on a wooden foot bridge in the interiors of Dal Lake in Srinagar on January 16, 2017. A cold wave has further tightened its grip in Jammu and Kashmir, with most places in the state recording sub-zero temperatures. (Photo by Tauseef Mustafa/AFP Photo)