package yukicorder;
import java.util.Scanner;

public class QNo279 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int num =0;
		char[] charas = s.toCharArray();
		for(int i=0;i<charas.length;i++){
			if(Character.isDigit(charas[i])){
				num += Character.getNumericValue(charas[i]);
			}
		}
		
		System.out.println(num);
	}

}