#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int INF = 1LL << 30;
int MOD = 1e9+7;
main(){
    string S;
    int cnt = S.size();
    cin >> S;
    for(char c:S)if(c != '0')cnt--;
    cout << abs(cnt - 7) << endl;
}