11332 - Summing Digits

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

class Main {

int GetDigit(int number)
{
//System.out.println(number);
int sum=0;
if(number<10)
return number;


while((number/10)>0)
{
sum+=number%10;
number=number/10;
}

sum+=number;
return GetDigit(sum);
}

public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub

String input;
        Main digitCounting=new Main();
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
       
        while ((input=br.readLine()) != null)
{
 if(input.compareTo("0")==0)
 break;
 else
System.out.println(digitCounting.GetDigit(Integer.parseInt(input)));

}

}

}