public abstract class A { private static int n; public A() { A.n++; } public static int getN() { return A.n; } } public class B extends A{} public class C extends A{} public class Test public static void main(String[] args) { A b = new B(); System.out.println(A.getN()); // Prints 1 A c = new C(); System.out.println(A.getN()); // Prints 2 } ...