Problem:
Sum of Numbers

Write a program which reads an integer and prints sum of its digits.

Input

The input consists of multiple datasets. For each dataset, an integer x is given in a line. The number of digits in x does not exceed 1000.

The input ends with a line including single zero. Your program should not process for this terminal symbol.

Output

For each dataset, print the sum of digits in x.

Sample Input

123
55
1000
0

Sample Output

6
10
1

Solution in JAVA (judge verdict: Runtime Error)

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        while(sc.hasNext()) {

            int a = sc.nextInt();
            int sum = 0;

            for (int i=1; ;i++){
                int b = a % 10;
                a = (a-b)/10;
                sum = sum + b;
                if(a==0)
                    break;
            }
            if(sum==0)
                break;

            System.out.printf("%d\n",sum);
        }
    }
}