List IntegerSetIntersection(List& A, List& B) {
    List res;
    Init(res);

    Reset(A);
    Reset(B);
    Reset(res);

    for (ListItem* i = A.Head; i != NULL; i = i->Next)
    {
        if (IntegerSetIsMember(B,i->Value) && !IntegerSetIsMember(res,i->Value))
        {
            IntegerSetAdd(res, i->Value);
        }
    }

    return res;
}