import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
    String [] n = sc.next().split("");
    int count  = 0;
      for (int i = 0; i < n.length; i++) {
        if (n[i].equals("0")) {
          count ++;
        }
      }
      System.out.println(Math.abs(8 - count));
		sc.close();
    }
}