In Siberia, Zhenya and his friends are known simply as the "cellar children".
They have escaped drugs, alcoholism and violence at home to find themselves surviving, huddled in filthy cellars, in the harsh, numbing cold of a Russian winter.
These "cellar children" live, largely ignored, on the margins of one of Russia's most isolated cities, Chita. Lying 3,000 miles east of Moscow, Chita now survives as an important stopover on the last leg of the trans-Siberian railway.
For Zhenya, December on the blizzard-whipped streets of Chita means enduring temperatures that plummet to -30C at night.
Just 12, he smokes a packet of filterless cigarettes a day, enjoys strong beer, inhales solvents and talks like someone 10 years older. "I just want to escape all this," he says. "And I'm trying. I have my worst moments after I've been inhaling. I don't think I'll make it to 50."
Zhenya has lived in a cellar beneath a grim Soviet-era housing block, and others like it, for two years now - one of dozens of destitute young boys and girls helped every week by a charity called Helping Hand.
A Pentecostal church-linked organisation run by a former policeman called Andrei Kovalev, it is heavily funded by the Railway Children, the innovative and pioneering British charity chosen for this year's Independent on Sunday Christmas Appeal.
Set up by a former British Rail executive, David Maidment, the Railway Children ploughs money into helping to save street children who attach themselves to rail and bus stations in places like Chita, Moscow, India and the UK.
And for children like Zhenya Prosyannikov, Helping Hand is probably their only chance of survival.
His story is typical. His mother, Valya, is an unemployed alcoholic and his father, Andrei, a heroin addict who pays for his habit by stealing. When a friend suggested they run away from their village and see the town of Chita, Zhenya did not hesitate.
"I thought it was a good idea then, but I regret it now," he says, his young eyes tearful. "On one occasion my father started to attack me with his slippers. Mum drank and dad did heroin. It was awful."
Now, Zhenya begs for money close to the Russian Orthodox church near the vast, spartan railway station - a pastel-coloured edifice dating back to before the revolution. On good days, he raises enough to use the station's canteen.
The day The Independent on Sunday met Zhenya, he had just been given something simple: a pair of winter boots, from Helping Hand.
Ira Pushkarova, 16, is another of the cellar children. She has been living on and off the streets for three years. Some days she summons up the courage to return home to her divorced, alcoholic mother, Luda. It never lasts.
Igor Bulkov, 17, was thrown out of his home by his alcoholic mother, Marina, three years ago.
His friend Petya Fidorov, 17, says his problems began about five years ago when his mother began to drink heavily and forced him to do the same, as well as becoming violent towards him. "That's when I left," he says. "Now I've got my mates [in the cellar]."
Petya says he wants to become a mechanic and is thinking about returning to a children's home. Like the others he also inhales solvents.
These youngsters often survive during the summer in and around Chita railway station, where at night they sleep under the railway bridges, sleeping on or close to the tracks. Chita's homeless adults squeeze under the platforms to lie on the hot water pipes underneath, leeching the heat.
But in winter, bleak cellars become home. Zhenya's is entered through a tiny square opening in an outside wall.
The "bathroom" is a filthy white metal tub in the corner of a low-ceilinged, concrete, graffiti-scrawled room.
The children are easy to spot. Dressed in ragged, grime-stained clothes, they have something of the feral about them and can be seen wandering around Chita's barren streets begging.
With money from the Railway Children, Helping Hand organises food runs three times a week, helps the children with advice and clothing, runs morale-boosting summer camps and attempts to get them off the streets and into some kind of training that might lead to a job.
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