By Matt Prodger
BBC correspondent in Belgrade
The Saiti family, like many of the 10 million Roma (Gypsies) in central and eastern Europe, are struggling against poverty and discrimination.
International Roma Day, on 8 April, is aimed at raising awareness of the problems facing Roma.
The Saitis: Neglected by the Serbian welfare system
In central Belgrade the Saitis live on the wrong side of the tracks.
Their home is a cardboard hut perched beside a railway.
Shaban Saiti, 32, has a wife, four children and little else apart from a cannibalised Citroen car, which he calls his "Beloved Dyana".
Together they make up a familiar sight in Belgrade. Shaban spends his days driving round the streets searching for rubbish - anything - to sell.
Struggle to survive
In Serbia and Montenegro the Roma effectively recycle the country's entire household waste, selling on everything from old shoes to broken hairdryers.
But Shaban says it is a matter of survival, not choice.
"I spend the morning with my head in dustbins looking for things to sell on the street. Sometimes I find something, sometimes I don't. If I don't, then me and my family just have to suffer in silence."
Today is a good day. Shaban finds some old shoes, and even a broken computer. But his prize find is a batch of fruit juice discarded by a restaurant because it is a month past its sell-by date. That will help feed his family.
Shaban's "Beloved Dyana": A cannibalised Citroen car
At a roadside market he sells what he can and makes $2 - enough for petrol to get him home, but not much more.
Human rights groups say there are around half a million Roma in Serbia, while the government estimates far fewer.
To register for state assistance, they need a valid address. But most do not have one because their encampments are illegal.
Petar Antic, a Romani lawyer working for the Minority Rights Centre in Belgrade, says there are "the obvious problems like job discrimination, and attacks on Roma by skinheads and thugs".
"But our main priority is to get the Roma registered so that they can get homes, access to healthcare and education. It's a myth that they somehow want to live on the margins of society. They want what everybody else has, but they can't get it."
In recent months the government of Serbia and Montenegro has said it will take steps to improve the position of the country's Roma population.
Many of the people in Shaban's railside slum are Roma refugees from the war in Kosovo six years ago.
Life on the tracks: Sickness blights the children's lives
They live a life without electricity, without running water, and always with the threat of being moved on. Most of them have no identity cards - no official record of them exists.
And that makes them vulnerable. A minority of Serbs would like to see the back of the Roma.
Shaban's wife Merima tells me that when darkness falls some people - mostly drunks and drug addicts, she says - come down to the slum to throw stones and bottles at them. Others call them names.
"We're frightened they'll burn down our home, because it's only made of cardboard and wood," she says. "At night we make sure all the children are in one room and one of the adults always stays awake to keep watch."
The Saiti children are already suffering from ill health.
Ten-year-old Hanunshi has a heart condition. She is small for her age, and wheezes as she sleeps on a pile of blankets. Her parents say they have no money for medicine.
Along with her brothers and sisters, she faces an uncertain future as the poorest citizens in one of Europe's poorest countries.