Migrants climb through the windows of a train bound for Serbia at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 19 July 2015. Thousands of migrants who crossed Greece are on their way through Macedonia towards Serbia in order to access other European countries. Hungary in mid-July started to put up a fence on its border with Serbia, which makes the situation with the migrants in the transit countries even more complicated. The European countries on 20 July will discuss the quota of how many migrants each country should accept. (Photo by Georgi Licovski/EPA)

Children, wearing red neckerchiefs, a symbol of the Pioneer Organization, salute during a ceremony for the inauguration of 18 new members at a local school in the southern settlement of Kazminskoye in Stavropol region, Russia, November 19, 2015. Early pro-communist youth movements, which appeared in Russia after the 1917 Bolshevik revolution, were reformed into the Pioneer Organization of the Soviet Union. While the organization lost its dominance among students in post-Soviet Russia, some educational institutions and families still carry on this tradition. (Photo by Eduard Korniyenko/Reuters)

A female soccer player controls a ball during a training session at the Golab Trust Sport Complex in Kabul March 10, 2014. Despite decades of conflict in Afghanistan, and several recent militant attacks, the country's capital Kabul is home to a vibrant youth scene of musicians, artists, athletes and activists. Shopping malls and cafes stand in the city, which is nonetheless beset by infrastructure problems and instability. (Photo by Morteza Nikoubazl/Reuters)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group attack pushers of spice, a synthetic drug, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this Wednesday, April 8, 2020, photo, youths remove their mask to record a dance routine on the streets of Wuhan in central China's Hubei province. Released from their apartments after a 2 1/2-month quarantine, residents of the city where the coronavirus pandemic began are cautiously returning to shopping and strolling in the street but say they still go out little and keep children home while they wait for schools to reopen. (Photo by Ng Han Guan/AP Photo)

The Queen Elizabeth Tower (Big Ben) is reflected in a puddle as a cyclist rides by in London, on 27 June 2016. Britain began preparations to leave the European Union on Monday but said it would not be rushed into a quick exit, as markets plunged in the wake of a seismic referendum despite attempts to calm jitters. (Photo by Leon Neal/AFP Photo)

A protester jumps on the table in front of the European Central Bank President Mario Draghi during a news conference in Frankfurt, April 15, 2015. The news conference was disrupted on Wednesday when a woman in a black T-shirt jumped on the podium. (Photo by Kai Pfaffenbach/Reuters)

A pilot looks up from a U.S. F-22 Raptor fighter as it prepares to refuel in mid-air with a KC-135 refuelling plane over European airspace during a flight to Britain from Mihail Kogalniceanu air base in Romania April 25, 2016. (Photo by Toby Melville/Reuters)