public static void main(String[] args) {
        for(int i =0;i< 9;i++){
            for (int j =0;j < 9 ; j++) {
                int val = i/3*3 + j/3;
                System.out.print(val +" ");
            }
            System.out.println();
        }
        System.out.println("Hello world");
    }