import java.util.Scanner;

public class No_289 {
	static String[] numbers = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" };

	static boolean checkOfWord(String c) {
		for (String n : numbers) {
			if (c.equals(n)) {
				return true;
			}
		}
		return false;
	}

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int sum = 0;

		for (int i = 0; i < s.length(); i++) {
			String check = s.substring(i, i + 1);
			if (checkOfWord(check)) {
				int j = Integer.parseInt(check);
				sum += j;
			}
		}
		System.out.println(sum);
		sc.close();

	}

}