The movie I have wtched

I once watched a movie, which was about four children.  Their mother gave birth to them but she didn’t get married, so she didn’t let anyone know her children’s presence.  They lived in a small apartment and they stayed at home all day instead of going to school when their mother was working.  One day, they got up and found that their mother had gone with some money left.  They believed that she would come back soon, so they waited patiently.  However, she didn’t come back after a long time, and the children were gradually running out of money.  One day, the eldest son called their mother up only to found that she had got married.  Their house became mess and dirty, moreover, water and electronic was cut off because they couldn’t pay the rent.  With time passing by, they began feeling despair and worried, however, as no one knew them, they couldn’t get any help.  One day, the youngest sister fell down and died.  Not knowing what to do, his brother could only bury her secretly with a girl they met in a park.  It was a sad story and I think what the children faced was very impressive.