#include <bits/stdc++.h>

#define FOR(n, a, b) for(size_t n = (a); n < (b); ++n)
#define ALL(x) x.begin(), x.end()
#define pb push_back
#define st first
#define nd second

using namespace std;

typedef long long ll;
typedef pair<int, int> pint;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pint> vii;

unsigned long long n;
string s;



int first_zero(bitset<40> b) {
    for(int i = s.size() - 1; i >= 0; --i) {
        if(b[i] == 0) return s.size() - 1 - i;
    }
    return -1;
}


int solve(bitset<40> b, int max_depth) {
    int k = first_zero(b);
    if(k == -1) return 0;
    if(k >= 20) return 1;

    if(max_depth == 1) return max_depth;

    int min_d = max_depth;
    for(int i = 1; i <= k; i++) {
        min_d = min(min_d, solve(b | b>>i, max_depth-1));
    }
    return min_d + 1;
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin >> s;
    bitset<40> b(s);
    // cout << first_zero(b) << '\n';
    n = s.size();
    int offset = 0;
    if(b[n-1] == 0) {
        cout << -1 << '\n';
        return 0;
    }
    if(n > 1 && b[n-2] == 0) {
        b = b | b>>1;
        offset = 1;
    }

    cout << solve(b, 5) + offset << '\n';

    // cout << check(s) << '\n';

    return 0;
}