package yukiCoder;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No00289 {
	public static void main(String args[]) {
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

		try {
			String input = bufferedReader.readLine();

			int ans = sum(input);

			System.out.println(ans);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	static int sum(String input) {
		int ans = 0;
		for (int i = 0 ; i < input.length() ; i++) {
			if (Character.isDigit(input.charAt(i))) ans += Character.getNumericValue(input.charAt(i));
		}
		return ans;
	}
}