#include <stdio.h>
#include <vector>
#include <string.h>
#include <algorithm>
#include <string>
#include <map>

using namespace std;

#define REP(A,B) for(int (A)=0;(A)<(B);(A)++)
char str[44];
string S;
int best = 5;
string S2;
int n;
void dfs(long long val, int dist) {
	//printf("%lld %d\n", val, dist);
	if(val == (1LL<<n)-1) {
		best = min(best, dist);
		return;
	}
	if(dist == 4)
		return;
	for(int i = 1; i < n; i++) {
		long long nval = val | (val>>i);
		dfs(nval, dist+1);
	}
}
int main()
{
	scanf("%s", str);
	S = string(str);
	n = strlen(str);
	if(str[0] == '0') {
		printf("-1\n");
		return 0;
	}
	if(n >= 33) {
		bool allzero = true;
		for(int i = 1; i <= 32; i++)
			if(str[i] != '0')
				allzero = false;

		if(allzero) {
			printf("6\n");
			return 0;
		}
	}
	long long val = 0;
	REP(i, n) val = 2*val + (S[i] == '1');
	dfs(val, 0);
	printf("%d\n", best);
	return 0;
}