import java.io.*;
   
public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        String line;
        LOOP: while ((line = input.readLine()) != null) {
            int line_len = line.length();
            if (line_len == 1 && line.charAt(0) == '0')
                break LOOP;
            long total = 0;
            for (int i = 0; i < line_len; i++) {
                int ival = Character.getNumericValue(line.charAt(i));
                if (ival >= 0)
                    total += ival;
                // total += line.charAt(i) - '0';
            }
            System.out.println(total);
        }
    }
}
/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