import java.util.*;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String S = sc.next();

		char charS[] = S.toCharArray();
		int cnt = 0;
		
		for(int i = 0;i < charS.length; i++) {
			if(charS[i] == '1' ||
			   charS[i] == '2' ||
		       charS[i] == '3' ||
			   charS[i] == '4' ||
			   charS[i] == '5' ||
			   charS[i] == '6' ||
			   charS[i] == '7' ||
			   charS[i] == '8' ||
			   charS[i] == '9') {
				cnt+=Integer.parseInt(String.valueOf(charS[i]));
			}
		}
		
		System.out.println(cnt);
	}
}