import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		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);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		System.out.println(sum);
	}
} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		System.out.println(sum);
	} main {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		System.out.println(sum);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String s = scan.next(); s scan.next() scan.next scan int sum = 0; sum 0 for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		} int i = 0; int i = 0; i 0 i < s.length() i s.length() s.length s i++ i++ i {
			sum += s.charAt(i)-'0';
		} {
			sum += s.charAt(i)-'0';
		} sum += s.charAt(i)-'0' sum s.charAt(i)-'0' s.charAt(i) s.charAt s i '0' 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);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		System.out.println(sum);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		System.out.println(sum);
	}
} Main
import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		int sum = 0;
		for(int i = 0; i < s.length(); i++){
			sum += s.charAt(i)-'0';
		}
		System.out.println(sum);
	}
}