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

class AbstractList<A> extends List<A>
{
    A a = null;
}

class Vektor<A> extends AbstractList<A>
{
    A a = null;
}

class Stack<A> extends Vektor<A>
{
    A a = null;
}

class Objekt
{
}

class Int
{
}

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


class otth16
{
}