class DD<B, A>
{
    A a = null;
    B b = null;
}

class CC<A>
{
    A a = null;
}

class BB< A > extends CC<A>
{
    A a = null;
}

class AA<A, B> extends BB< DD<B, A> >
{
    A a = null; 
    B b = null;
}

class otth17
{
}