import java.io.*;

class Process {
    private String S;

    Process(String S) {
        this.S = S;
    }

    private boolean isNumber(char c) {
        return ((c >= '0') && (c <= '9'));
    }

    int getResult() {
        int sum = 0;
        
        for(int i = 0; i < S.length(); i++) {
            if(!isNumber(S.charAt(i))) {
                continue;
            }

            sum += (int)(S.charAt(i) - '0');
        }
        
        return sum;
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        var bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        var printWriter    = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

        // 入力
        String S = bufferedReader.readLine().trim();

        // 処理および出力
        printWriter.println((new Process(S)).getResult());
        
        bufferedReader.close();
        printWriter.close();
    }
}