#include <bits/stdc++.h>
using namespace std;

#define FOR(a,b,c) for(int a = b; a < c; a++)

int N;
int res = 6;

void generate(bitset <40> b, int c)
{

	int cn = 0;

	FOR(i, 0, N)
	{
		if(b[i])
		{
			++cn;
		}
	}
	
	if(cn == N)
	{
		res = min(res, c);
		return;
	}

	if(c < 5)
	{
		FOR(i, 1, 21)
		{
			bitset <40> temp = b;
			temp |= temp << i;

			generate(temp, c + 1);
		}
	}
}

int main()
{
	ios_base::sync_with_stdio(0);
	
	string s;

	cin >> s;

	N = s.size();

	if(s[0] == '0')
	{
		cout << -1;
		return 0;	
	}

	bitset <40> mask;
	
	FOR(i, 0, N)
	{
		if(s[i] == '1')
		{
			mask[i] = 1;
		}
	}

	generate(mask, 0);

	cout << res;

	return 0;
}