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

public class Main {
	
	public static void main(String[] args){
		
		BufferedReader insBR = new BufferedReader(new InputStreamReader(System.in));
		//?????????????????????char[]?????¬????????§??????????´????????????????list??????
		ArrayList<char[]> list = new ArrayList<char[]>();
		
		try {
			boolean isContinue = true;
			while(isContinue){
				
				String strLine = insBR.readLine();
				if(!"0".equals(strLine)){
					//?????§???????????°???char[]???????§£??????list???????´?
					char[] ary = strLine.toCharArray(); 
					list.add(ary);
				}else{
					isContinue = false;
				}
			}
		} catch (IOException e) {
			// TODO ????????????????????? catch ????????????
			e.printStackTrace();
		}
		
		//char[]???int[]?????\?????´???
		
		for(int i = 0; i < list.size(); i++){
			//?????????????¨?????????\???????????°
			int intSumNum = 0;
					
			char[] ary = list.get(i);
			for(int j = 0; j < ary.length; j++){
				//char??????int??????????????????????????????
				int intNum = 0;
				intNum = Character.getNumericValue(ary[j]);
				intSumNum += intNum;
			}
			//??????
			System.out.println(intSumNum);
		}
		
	}
}
/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