
import java.util.Scanner;
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
			while(sc.hasNext()) {
				String x = sc.nextLine();
				if(x.equals("0")) {
					break;
				}
				String strA ="";
				int Sum = 0;
				for(int i = 0; i < x.length(); i++) {
					strA = x.substring(i,i+1);
					Sum += Integer.parseInt(strA);
				}
				System.out.println(Sum);
			}
	}
}
/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