#include <iostream>
#include <cstring>
using namespace std;
typedef long long ll;
string s;
const int INF = 1e9;
bool check_if_power_of_5(string num) {
    if(num[0] == '0') {
        return false;
    }
    ll power_of_two = 1;
    ll res = 0;

    for(int i = (int) num.size() - 1; i >= 0; i--) {
        if(num[i] == '1') {
            res += power_of_two;
        }
        power_of_two *= 2;
    }

    bool is_power_of_5 = true;
    while(res > 1) {
        if(res % 5 != 0) {
            is_power_of_5 = false;
            break;
        }
        res /= 5;
    }
    return is_power_of_5;
}
int  dp[55];
int rec(int at) {
    if(at >= (int) s.size()) {
        return 0;
    }
    if(dp[at] != -1) {
        return dp[at];
    }

    string tmp = "";
    int res = INF;
    for(int i = at; i < (int) s.size(); i++) {
        tmp += s[i];
        if(check_if_power_of_5(tmp)) {
            res = min(res, rec(i + 1) + 1);
        }
    }

    dp[at] = res;
    return res;

}
int main()
{
    memset(dp, -1, sizeof dp);
    cin >> s;

    int res = rec(0);
    if(res >= INF) {
        res = -1;
    }
    cout << res << endl;

    return 0;
}