import java.io.*; import java.util.*; import java.math.BigInteger; public class Main { static void solve() { String str = in.next(); char[] s = str.toCharArray(); long ans=0; for(int i=0;i<s.length;i++) { if(s[i]=='0'||s[i]=='6'||s[i]=='9') ans++; else if(s[i]=='8') ans+=2; } out.println(ans); } public static void main(String[] args) { solve(); out.flush(); } static FastReader in = new FastReader(); static PrintWriter out = new PrintWriter(System.out); static class FastReader { static BufferedReader br; static StringTokenizer st; FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); } String next() { String str = ""; while(st==null||!st.hasMoreElements()) { try { str = br.readLine(); }catch(IOException e) { throw new RuntimeException(e); } st = new StringTokenizer(str); } return st.nextToken(); } int nextInt() { return Integer.parseInt(next()); } double nextDouble() { return Double.parseDouble(next()); } long nextLong() { return Long.parseLong(next()); } } }