import java.util.Scanner;
	

public class Main{
	
	
	public static void main(String args[])throws Exception{
		Scanner sc = new Scanner(System.in);

		String S = sc.next();
		int L = S.length();
		int ans = 0;
		for(int i=0;i<L;i++){
			char c = S.charAt(i);
			if('1'<=c&&c<='9'){
				ans += c-'1'+1;
			}
		}
		System.out.println(ans);
	}
	

}