#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define rep(i, a, n) for (int i = a; i < n; ++i)

int main() {
    string n;
    cin >> n;

    int cnt = 0;
    rep(i, 0, n.length()) {
        if (n[i] == '0') cnt++;
    }
    cout << abs(8 - cnt) << endl;
    return 0;
}