interface IntA {

	public void test_a();

}

interface IntB {

	public void test_b();

}

class TestA {

	public void test_a() {
		print("Hello world from TestA::test_a().\n");
	}

}

class TestB {

        public void test_b() {
                print("Hello world from TestB::test_b().\n");
        }


}

class TestC {

        public void test_c() {
                print("Hello world from TestC::test_c().\n");
        }

}

class TestD {

        public void test_a() {
                print("Hello world from TestD::test_a().\n");
        }

}

class TestE {

        public void test_b() {
                print("Hello world from TestE::test_b().\n");
        }

}

class Program extends TestE, TestD, TestC, TestB, TestA implements IntA, IntB {

	public void main() {
		$this->test_a();
		$this->test_b();
		$this->test_c();
	}

}