import java.util.Scanner;


public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	}

} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	} main {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		} true {
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		} String x = scan.next(); x scan.next() scan.next scan if(x.equals("0")){
				break;
			} x.equals("0") x.equals x "0" {
				break;
			} break; int sum = 0; sum 0 for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			} int i = 0; int i = 0; i 0 i < x.length() i x.length() x.length x i++ i++ i {
				sum += Character.digit(x.charAt(i), 10);
			} {
				sum += Character.digit(x.charAt(i), 10);
			} sum += Character.digit(x.charAt(i), 10) sum Character.digit(x.charAt(i), 10) Character.digit Character x.charAt(i) x.charAt x i 10 System.out.println(sum) System.out.println System.out System System.out sum String[] args args public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	}

} public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	}

} Main
import java.util.Scanner;


public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		while(true){
			String x = scan.next();
			if(x.equals("0")){
				break;
			}
			int sum = 0;
			for(int i = 0; i < x.length(); i++){
				sum += Character.digit(x.charAt(i), 10);
			}
			System.out.println(sum);
		}

	}

}