/*
                                                                                                     
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            .:ooo+++++osso-`    `.:-...`/` ./::-------:/:`   -`         :+--..``````.--:+:...-+:-`  
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                                          `-+o+/:---:/+o/.                                          
                                            `.:+oooo+/-.`                                           
                                               ``````                                               
*/


#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <set>
#include <queue>
#include <ostream>
#include <istream>
#include <typeinfo>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <limits>
#include <fstream>
#include <array>
#include <list>
#include <bitset>
#include <functional>

#define mt make_tuple
#define x first
#define y second
#define pb push_back
#define ppb pop_back
#define pf push_front
#define ppf pop_front
#define mp make_pair
#define umap unordered_map
#define uset unordered_set
#define rt return 0;
#define elif else if
#define len(v) ((int)v.size())


using namespace std;

char string_in_buffer[(int)1e5];


void fast_scan(int &x) { scanf("%d", &x); }
void fast_scan(long long &x) { scanf("%lld", &x); }
void fast_scan(unsigned long long &x) { scanf("%llu", &x); }
void fast_scan(double &x) { scanf("%lf", &x); }
void fast_scan(long double &x) { scanf("%Lf", &x); }
void fast_scan(char &x) { 
	scanf("%c", &x); 
	if (x == '\n') {
		fast_scan(x);
	}
}
void fast_scan(string &x) {
	scanf("%s", string_in_buffer);
	x = string(string_in_buffer);
}

template<class TFirst, class TSecond>
void fast_scan(pair<TFirst, TSecond> &p) {
	fast_scan(p.first);
	fast_scan(p.second);
}

template <class T>
void fast_scan(vector<T> &v) {
	for (auto &x : v) fast_scan(x);
}

void fast_print(const int &x) { printf("%d", x); }
void fast_print(const long long &x) { printf("%lld", x); }
void fast_print(const unsigned long long &x) { printf("%llu", x); }
void fast_print(const double &x) { printf("%.15lf", x); }
void fast_print(const long double &x) { printf("%.15Lf", x); }
void fast_print(const char &x) { printf("%c", x); };
void fast_print(const string &x) { printf("%s", x.c_str());}

template<class TFirst, class TSecond>
void fast_print(const pair<TFirst, TSecond> &p) {
	fast_print(p.first);
	fast_print(' ');
	fast_print(p.second);
}

template <class T>
void fast_print(const vector<T> &v) {
	if (v.empty()) return;
	fast_print(v[0]);
	for (int i = 1; i < v.size(); i++) {
		fast_print(" ");
		fast_print(v[i]);
	}
}

template <class T>
void fast_print(const vector<vector<T>> &v) {
	if (v.empty()) return;
	fast_print(v[0]);
	for (int i = 1; i < v.size(); i++) {
		fast_print("\n");
		fast_print(v[i]);
	}
}



using namespace std;


namespace smart_io {
	string print_start = "";
	string sep = " ";
	bool first_print = false;

	void precall_print() {
		fast_print(print_start);
		print_start = "\n";
		first_print = true;
	}
} //namespace smart_io


template <class T>
ostream &operator,(ostream &os, const T &object) {
	if (!smart_io::first_print) {
		fast_print(smart_io::sep);
	} else {
		smart_io::first_print = false;
	}
	fast_print(object);
	return os;
}

template <class T>
istream &operator,(istream &is, T &object) {
	fast_scan(object);
	return is;
}

namespace typedefs {
	typedef long long ll;
	typedef unsigned long long ull;
	typedef pair<int, int> pii;
	typedef long double ld;
}

namespace numbers_operation {
	template<class T>
	T floor_mod(T a, T b) {
		if (a % b == 0) return 0;
		if (a >= 0 && b >= 0) return a % b;
		if (a <= 0 && b <= 0) return a % b;
		return abs(b) - (abs(a) % abs(b));
	}
}

using namespace numbers_operation;
using namespace typedefs;

#define print    \
smart_io::precall_print(); \
cout,

#define scan cin,


struct Elem {
	bool mone;
	bool value;
	int right, left;

	Elem() {

	}

	Elem(bool _mone, bool _value, int _left, int _right) {
		mone = _mone;
		value = _value;
		left = _left;
		right = _right;
	}
};

void shift_left(vector<Elem> &elems) {
	Elem first = elems[0];
	for (int i = 0; i < len(elems) - 1; i++) {
		elems[i] = elems[i + 1];
	}
	elems.back() = first;
}

void shift_right(vector<Elem> &elems) {
	Elem back = elems.back();
	for (int i = len(elems) - 1; i > 0; i--) {
		elems[i] = elems[i - 1];
	}
	elems[0] = back;
}

int find_kek(vector<pii> keks) {
	if (keks.empty()) return 0;
	sort(keks.begin(), keks.end());
	vector<int> pr(len(keks));
	pr.back() = keks.back().second;
	for (int i = len(pr) - 2; i > -1; i--) {
		pr[i] = max(keks[i].second, pr[i + 1]);
	}
	int _min = 1e9;
	for (int i = 0; i < len(keks) - 1; i++) {
		_min = min(_min, keks[i].first + pr[i + 1]);
	}
	return min(min(_min, keks.back().first), pr[0]);
}

signed main(signed argc, char *argv[]) {
	string a;
	string b;
	scan a, b;

	int n = len(a);
	bool full_zero_b = true;
	bool full_zero_a = true;
	for (int i = 0; i < n; i++) {
		if (b[i] == '1') {
			full_zero_b = false;
		}
		if (a[i] == '1') {
			full_zero_a = false;
		}
	}

	if (full_zero_b) {
		if (full_zero_a) {
			print 0;
		} else {
			print -1;
		}
		return 0;
	}
	
	int stl = 1e9;
	for (int i = n - 1; i > -1; i--) {
		if (b[i] == '1') {
			stl = n - i;
			break;
		}
	}

	vector<int> dleft(n);
	dleft[0] = (b[0] == '1') ? 0 : stl;	
	for (int i = 1; i < n; i++) {
		dleft[i] = (b[i] == '1') ? 0 : dleft[i - 1] + 1;
	}

	int str = 1e9;
	for (int i = 0; i < n; i++) {
		if (b[i] == '1') {
			str = i + 1;
			break;
		}
	}

	vector<int> dright(n);
	dright[n - 1] = (b[n - 1] == '1') ? 0 : str;
	for (int i = n - 2; i > -1; i--) {
		dright[i] = (b[i] == '1') ? 0 : dright[i + 1] + 1;
	}

	int _min = 1e9;
	{
		vector<Elem> all;
		for (int i = 0; i < n; i++) {
			all.emplace_back(b[i] == '1', a[i] == '1', dleft[i], dright[i]);
		}

		for (int shift = 0; shift <= n; shift++) {
			for (int i = 0; i < n; i++) {
				if (b[i] == '1') {
					all[i].mone = true;
				}
			}
			vector<pii> keks;
			int cur = shift;
			for (int i = 0; i < n; i++) {
				if (b[i] == '1') {
					if (all[i].value) {

					} else {
						cur++;
					}
				} else {
					if (all[i].value) {
						if (all[i].mone) {
							cur++;
						} else {
							cur++;
							keks.emplace_back(dleft[i] * 2, all[i].right * 2);
						}
					}
				}
			}

			cur += find_kek(keks);

			_min = min(_min, cur);
			shift_left(all);
		}
	}

	{
		vector<Elem> all;
		for (int i = 0; i < n; i++) {
			all.emplace_back(b[i] == '1', a[i] == '1', dleft[i], dright[i]);
		}

		for (int shift = 0; shift <= n; shift++) {
			for (int i = 0; i < n; i++) {
				if (b[i] == '1') {
					all[i].mone = true;
				}
			}
			vector<pii> keks;
			int cur = shift;
			for (int i = 0; i < n; i++) {
				if (b[i] == '1') {
					if (all[i].value) {

					} else {
						cur++;
					}
				} else {
					if (all[i].value) {
						if (all[i].mone) {
							cur++;
						} else {
							cur++;
							keks.emplace_back(dright[i] * 2, all[i].left * 2);
						}
					}
				}
			}

			cur += find_kek(keks);

			_min = min(_min, cur);
			shift_right(all);
		}
	}

	print _min;
}

Measured memory_bytes: 384