/*No.289 数字を全て足そう*/
import java.io.*;
public class No289 {
	public static void main(String[] args) {
		String r_moji,moji;
		int result=0;
		try(BufferedReader input =new BufferedReader(new InputStreamReader(System.in))){
			r_moji=input.readLine();
			for(short i=0;i<r_moji.length();i++){
				moji=r_moji.substring(i, i+1);
				if(moji.codePointAt(0)>=48 &&moji.codePointAt(0)<=57){
					result+=Integer.parseInt(moji);
				}
			}
			System.out.println(result);
		}catch(Exception e){
			e.printStackTrace();
		}
	}
}