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 C# (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication12
{

    //ONLINE JUDGE (ITP1_8_B)


    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                string str = Console.ReadLine();
                int x = int.Parse(str);
                
                if ((x == 0) || (x >= 10000))
                {
                    break;
                }

                int sum = 0;
                for (int i = x; i > 0; i /= 10)
                {
                    int a = (i % 10);
                    sum += a;
                    i -= a;
                }
                Console.WriteLine(sum);
            }
        }
    }
}