import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Scanner;
import javax.sound.midi.SysexMessage;
  
public class Main{      
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int i = 0;
        for(;i<1000;i++){
            int ans=0;
            BigInteger m = sc.nextBigInteger();
            if(m.compareTo(BigInteger.ZERO)==0)
                break;
            int len = String.valueOf(m).length();
            for (int j = 0; j<len; j++)
            {
                ans += Character.getNumericValue(String.valueOf(m).charAt(j));
            }
            System.out.println(ans);  
        }
       
    }
}              

    

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz