#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
void Say(bool say, string a = "Yes", string b = "No"){cout << (say ? a : b) << endl;};

int main(){
    string s;
    cin >> s;
    cout << abs(8 - count(s.begin(), s.end(), '0')) << endl;
    return 0;
}