public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
 
        while (in.hasNextLine()){
            String str = in.nextLine();
            int n = 0;
            for (int i = 0; i < str.length(); i++) {
                switch (str.charAt(i)) {
                    case '0':
                    case '6':
                    case '9':n++;break;
                    case '8':n += 2;break;
                }
            }
            System.out.println(n);
        }
 
 
        in.close();
    }
}