取一个数字数字后4位的和

public static void main(String[] args) {
        while (true) {
            System.out.println("请输入一个数字");
            Scanner sc = new Scanner(System.in);
            long b = sc.nextLong();
//                int x = 121;
//               int b = x%10000;
//                int qian = b / 1000;
//                int bai = b % 1000 / 100;
//                int shi = b % 1000 % 100 / 10;
//                int  ge = b % 1000 % 100 % 10;
            long ge = b % 10;
            long shi = b / 10 % 10;
            long bai = b / 100 % 10;
            long qian = b/ 1000 % 10;
            long add = qian + bai + shi + ge;
                //System.out.println("四位数的和是" + (qian + bai + shi + ge) + "\n");
                System.out.println("后四位数的和是" +add+ "\n");

            }
        }
    }