interface A {
	void display(String s);
}

interface B {
	void display(int i);
}

class C1 implements A {
	public void display(String s) {
		System.out.println( "C1: " + s );
	}
}

class C11 extends C1 implements B {
	public void display(int i) {
		System.out.println( "C11: " + i );
	}
}

class C12 extends C1 implements B {
	public void display(int i) {
		System.out.println( "C12: " + i );
	}
}

class C2 implements A {
	public void display(String s) {
		System.out.println( "C2: " + s );
	}
}

class IRV {
	public static void main(String args[]) {
		A a;
		B b;
		a = new C1();
		a.display( "String 1" );
		a = new C2();
		a.display( "String 2" );
		a = new C11();
		b = new C11();
		a.display( "String 11" );
		b.display(5);
		a = new C12();
		b = new C12();
		a.display( "String 12" );
		b.display(10);
	}
}