import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	}
}
 import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	} main {
		Scanner sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		} true {
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		} String a = sc.next(); a sc.next() sc.next sc if(a.equals("0"))break; a.equals("0") a.equals a "0" break; int b b sum=0; sum 0 for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			} int i=0; int i=0; i 0 i<a.length() i a.length() a.length a i++ i++ i {
				b = a.charAt(i) - '0';
				sum += b;
			} {
				b = a.charAt(i) - '0';
				sum += b;
			} b = a.charAt(i) - '0' b a.charAt(i) - '0' a.charAt(i) a.charAt a i '0' sum += b sum b 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 sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	}
} public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	}
} Main
import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		while(true){
			String a = sc.next();
			if(a.equals("0"))break;
			int b,sum=0;
			for(int i=0;i<a.length();i++){
				b = a.charAt(i) - '0';
				sum += b;
			}
			System.out.println(sum);
		}
	}
}

