class A
{
public void f()
{
System.out.printf("AAAA\n");
}
}
class B extends A
{
public void f()
{
System.out.printf("BBBB\n");
}
}
class C extends B
{
public void f()
{
System.out.printf("CCCC\n");
}
}
class D extends C
{
public void f()
{
System.out.printf("DDDD\n");
}
}
public class TestPoly_1
{
public static void g(A aa)
{
aa.g();
}
public static void main(String[] args)
{
A aa = new A();
B bb = new B();
C cc = new C();
D dd = new D();
