#ifndef __VECTOR_UTIL_H__
#define __VECTOR_UTIL_H__

/* updated: 2020-03-22 */

#include <cassert>
#include <vector>
#include <string>
#include <iostream>
#include <algorithm>
#include <numeric>
#include <limits>

template <class T>
std::vector<T> inputVector(int size, std::istream& ist = std::cin);
template <class T>
std::vector<std::vector<T>> inputVector2D(int height, int width, std::istream& ist = std::cin);
template <class T>
void outputVector(const std::vector<T>& vec, const std::string& delimiter = " ", std::ostream& ost = std::cout);
template <class T>
std::vector<T> makeVector(int size, const T& value);
template <class T, class Func>
void apply(std::vector<T>& vec, Func func);
template <class T, class BinaryFunc>
std::vector<T> elementwise(std::vector<T>& a, std::vector<T>& b, BinaryFunc func);
template <class T>
void sortAndUnique(std::vector<T>& vec);
template <class T>
int mex(const std::vector<T>& vec);
template <class T, class Pred>
std::vector<int> sortWithInverse(std::vector<T>& vec, Pred pred);
template <class T>
std::vector<int> sortWithInverse(std::vector<T>& vec);

template <class T>
T maxOf(const std::vector<T>& vec);
template <class T>
T minOf(const std::vector<T>& vec);
template <class T>
T sumOf(const std::vector<T>& vec);
template <class T, class U>
U sumOf(const std::vector<T>& vec, const U& initial_value);

template <class T>
void sort(std::vector<T>& vec);
template <class T, class Pred>
void sort(std::vector<T>& vec, Pred pred);


/* 標準入力から値を受け取り vector を生成 */
template <class T>
std::vector<T> inputVector(int size, std::istream& ist) {
	std::vector<T> ret(size);
	for (int i = 0; i < size; ++i) {
		ist >> ret[i];
	}
	return ret;
}

/* 標準入力から値を受け取り2次元 vector を生成 */
template <class T>
std::vector<std::vector<T>> inputVector2D(int height, int width, std::istream& ist) {
	std::vector<std::vector<T>> ret(height, std::vector<T>(width));
	for (int i = 0; i < height; ++i) {
		for (int j = 0; j < width; ++j) {
			ist >> ret[i][j];
		}
	}
	return ret;
}

/* vector の内容を delimiter 区切りで出力 */
template <class T>
void outputVector(const std::vector<T>& vec, const std::string& delimiter, std::ostream& ost) {
	int size = vec.size();
	for (int i = 0; i < size; ++i) {
		ost << vec[i];
		if (i == size - 1) {
			ost << std::endl;
		} else {
			ost << delimiter;
		}
	}
}

/* vector 生成のヘルパー関数(主に多次元配列用) */
template <class T>
std::vector<T> makeVector(int size, const T& value) {
	return std::vector<T>(size, value);
}

/* vector の各要素に関数を適用する */
template <class T, class Func>
void apply(std::vector<T>& vec, Func func) {
	std::transform(vec.begin(), vec.end(), vec.begin(), func);
}

/* 2つの vector に対して要素ごとの演算を行って1つの vector を生成する */
template <class T, class BinaryFunc>
std::vector<T> elementwise(std::vector<T>& a, std::vector<T>& b, BinaryFunc func) {
	assert(a.size() == b.size());
	
	const int size = a.size();
	std::vector<T> ret(size);
	for (int i = 0; i < size; ++i) {
		ret[i] = func(a[i], b[i]);
	}
	return ret;
}

/* sort + unique O(n log n) */
template <class T>
void sortAndUnique(std::vector<T>& vec) {
	sort(vec.begin(), vec.end());
	auto it = unique(vec.begin(), vec.end());
	vec.erase(it, vec.end());
}

/* vector に含まれない非負整数のうち、最小のもの (minimum excluded) を得る O(n log n) */
/* template である必要ないかも */
template <class T>
int mex(const std::vector<T>& vec) {
	std::vector<int> copied(vec);
	sortAndUnique(copied);
	
	int value = 0;
	while (value < copied.size() && copied[value] == value) {
		++value;
	}
	return value;
}

/* ソート + 復元用の配列を生成 O(n log n) */
/* vector を破壊的ソート + 各要素のもともとの位置を格納した配列を返す */
template <class T, class Pred>
std::vector<int> sortWithInverse(std::vector<T>& vec, Pred pred) {
	std::vector<int> order(vec.size());
	std::iota(order.begin(), order.end(), 0);

	std::sort(order.begin(), order.end(), [&vec, pred](int i, int j) {
		return pred(vec[i], vec[j]);
	});

	std::vector<int> inverse(vec.size());
	for (int i = 0; i < vec.size(); ++i) {
		inverse[order[i]] = i;
	}

	/* in-place にしたい */
	std::vector<T> sorted;
	for (int i = 0; i < vec.size(); ++i) {
		sorted.emplace_back(std::move(vec[order[i]]));
	}
	vec = std::move(sorted);
	return inverse;
}

/* ソート + 復元用の配列を生成 O(n log n) : 比較関数なし */
template <class T>
std::vector<int> sortWithInverse(std::vector<T>& vec) {
	return sortWithInverse(vec, std::less<T>());
}

/* 最大値を取得, vector が空の場合は numeric_limits<T>::lowest を返す O(n) */
template <class T>
T maxOf(const std::vector<T>& vec) {
	T ret = std::numeric_limits<T>::lowest();
	for (const T& element : vec) {
		ret = std::max(ret, element);
	}
	return ret;
}

/* 最小値を取得, vector が空の場合は numeric_limits<T>::max を返す O(n) */
template <class T>
T minOf(const std::vector<T>& vec) {
	T ret = std::numeric_limits<T>::max();
	for (const T& element : vec) {
		ret = std::min(ret, element);
	}
	return ret;
}

/* 合計を取得, 戻り値の型は要素の型 O(n) */
template <class T>
T sumOf(const std::vector<T>& vec) {
	T ret = T();
	for (const T& element : vec) {
		ret += element;
	}
	return ret;
}

/* 合計を取得, 戻り値の型が要素の型と異なるときのための関数 O(n) */
template <class T, class U>
inline U sumOf(const std::vector<T>& vec, const U& initial_value) {
	U ret(initial_value);
	for (const T& element : vec) {
		ret += element;
	}
	return ret;
}

template<class T>
void sort(std::vector<T>& vec) {
	std::sort(vec.begin(), vec.end());
}

template<class T, class Pred>
void sort(std::vector<T>& vec, Pred pred) {
	std::sort(vec.begin(), vec.end(), pred);
}

#endif
#ifndef __MINMAX_H__
#define __MINMAX_H__

/* updated: 2020-08-02 */

#include <algorithm>
#include <functional>

/* 
// 最小値と最大値をビット演算の演算子オーバーロードで表記できるようにするクラス
// 演算子 | が max, 演算子 & が min を表す
// (扱うときは暗黙の型変換とオーバーロード解決に注意)
*/
template <class T, class Pred = std::less<T>>
class MinMax {
	T value_m = T();

public:
	MinMax() = default;
	MinMax(const T& value);
	MinMax(const MinMax<T, Pred>& other) = default;

	MinMax<T, Pred>& operator=(const T& value);
	MinMax<T, Pred>& operator=(const MinMax<T, Pred>& other) = default;

	MinMax<T, Pred>& operator|=(const T& other);
	MinMax<T, Pred>& operator&=(const T& other);

	operator T() const;
};

template <class T, class Pred>
MinMax<T, Pred> operator|(const MinMax<T, Pred>& a, const MinMax<T, Pred>& b);
template <class T, class Pred>
MinMax<T, Pred> operator&(const MinMax<T, Pred>& a, const MinMax<T, Pred>& b);
template <class T, class Pred, class U>
MinMax<T, Pred> operator|(const MinMax<T, Pred>& a, const U& b);
template <class T, class Pred, class U>
MinMax<T, Pred> operator&(const MinMax<T, Pred>& a, const U& b);
template <class T, class Pred, class U>
MinMax<T, Pred> operator|(const U& a, const MinMax<T, Pred>& b);
template <class T, class Pred, class U>
MinMax<T, Pred> operator&(const U& a, const MinMax<T, Pred>& b);

template<class T, class Pred>
MinMax<T, Pred>::MinMax(const T& value)
	: value_m(value) {
}

template<class T, class Pred>
MinMax<T, Pred>& MinMax<T, Pred>::operator=(const T& value) {
	value_m = value;
	return *this;
}

template<class T, class Pred>
MinMax<T, Pred>& MinMax<T, Pred>::operator|=(const T& other) {
	value_m = std::max(value_m, other, Pred());
	return *this;
}

template<class T, class Pred>
MinMax<T, Pred>& MinMax<T, Pred>::operator&=(const T& other) {
	value_m = std::min(value_m, other, Pred());
	return *this;
}

template<class T, class Pred>
MinMax<T, Pred>::operator T() const {
	return value_m;
}

template<class T, class Pred>
MinMax<T, Pred> operator|(const MinMax<T, Pred>& a, const MinMax<T, Pred>& b) {
	MinMax<T, Pred> ret(a);
	ret |= b;
	return ret;
}

template<class T, class Pred>
MinMax<T, Pred> operator&(const MinMax<T, Pred>& a, const MinMax<T, Pred>& b) {
	MinMax<T, Pred> ret(a);
	ret &= b;
	return ret;
}

template<class T, class Pred, class U>
MinMax<T, Pred> operator|(const MinMax<T, Pred>& a, const U& b) {
	return a | MinMax<T, Pred>(b);
}

template<class T, class Pred, class U>
MinMax<T, Pred> operator&(const MinMax<T, Pred>& a, const U& b) {
	return a & MinMax<T, Pred>(b);
}

template<class T, class Pred, class U>
MinMax<T, Pred> operator|(const U& a, const MinMax<T, Pred>& b) {
	return MinMax<T, Pred>(a) | b;
}

template<class T, class Pred, class U>
MinMax<T, Pred> operator&(const U& a, const MinMax<T, Pred>& b) {
	return MinMax<T, Pred>(a) & b;
}

using MMInt = MinMax<int>;
using MMLL = MinMax<long long int>;
using MMDouble = MinMax<double>;

#endif
#define _CRT_SECURE_NO_WARNINGS
#define _SCL_SECURE_NO_WARNINGS
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <utility>
#include <algorithm>
#include <functional>
#include <cmath>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <iomanip>
#include <sstream>
#include <bitset>
#include <limits>
#include <numeric>
#include <valarray>
#include <fstream>
#include <array>
#include <random>
#include <unordered_set>
#include <unordered_map>

using namespace std;
using uint = uint32_t;
using LL = int64_t;
using ULL = uint64_t;
using PP = pair<LL, LL>;
template <typename T> using PriorityQ = priority_queue<T, vector<T>, greater<T> >;
#define REP(i, a, n) for(LL i = (a), i##_max_ = (n); i < i##_max_; ++i)
#define REM(i, a, n) for(LL i = (LL)(n) - 1, i##_min_ = (a); i >= i##_min_; --i)
#define FLOAT fixed << setprecision(16)
#define SPEEDUP { cin.tie(NULL); ios::sync_with_stdio(false); }
const int INF = 0x3FFFFFFF;
const LL INFLL = 0x3FFFFFFF3FFFFFFF;
const double INFD = 1.0e+308;
const double EPS = 1.0e-9;

void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }
void YESNO(bool b) { cout << (b ? "YES" : "NO") << endl; }
template <class T, class U> istream& operator>>(istream& ist, pair<T, U>& right) { return ist >> right.first >> right.second; }
template <class T, class U> ostream& operator<<(ostream& ost, const pair<T, U>& right) { return ost << right.first << ' ' << right.second; }
template <class T, class TCompatible, size_t N> void Fill(T(&dest)[N], const TCompatible& val) { fill(dest, dest + N, val); }
template <class T, class TCompatible, size_t M, size_t N> void Fill(T(&dest)[M][N], const TCompatible& val) { for (int i = 0; i < M; ++i) Fill(dest[i], val); }
template <class T> T Next() { T buf; cin >> buf; return buf; }
istream& Ignore(istream& ist) { string s; ist >> s; return ist; }
bool Inside(int i, int j, int h, int w) { return i >= 0 && i < h&& j >= 0 && j < w; }

#ifdef ONLY_MY_ENVIR
#include "Accumulator.h"
#include "Algebraic.h"
#include "BinaryMatrix.h"
#include "BinaryTree.h"
#include "Bipartite.h"
#include "BIT.h"
#include "Compressor.h"
#include "Decompositions.h"
#include "DiscreteLog.h"
#include "DynamicMod.h"
#include "Exponential.h"
#include "Factorization.h"
#include "FFT.h"
#include "FlowSolver.h"
#include "Geometric2D.h"
#include "Geometric2DFloat.h"
#include "Geometric3D.h"
#include "Geometric3DFloat.h"
#include "Graph.h"
#include "GraphUtil.h"
#include "Interpolation.h"
#include "IntMod.h"
#include "KDTree.h"
#include "LazySegmentTree.h"
#include "LIS.h"
#include "List.h"
#include "Math.h"
#include "MathUtil.h"
#include "Matrix.h"
#include "MinCostFlowSolver.h"
#include "MinMax.h"
#include "Numbers.h"
#include "Optimize.h"
#include "Permutation.h"
#include "Polynomial.h"
#include "Position.h"
#include "Random.h"
#include "Range.h"
#include "Rational.h"
#include "RuntimeMod.h"
#include "SegmentTree.h"
#include "SegmentTree2D.h"
#include "Sets.h"
#include "Shortest.h"
#include "SlidingWindow.h"
#include "SpanningTree.h"
#include "StringSearching.h"
#include "SuffixArray.h"
#include "SwitchList.h"
#include "Timer.h"
#include "Tree.h"
#include "TreeUtil.h"
#include "UnionFind.h"
#include "Util.h"
#include "VectorUtil.h"
#endif

#ifdef __GNUC__
typedef __int128 LLL;
istream& operator>>(istream& ist, __int128& val) { LL tmp; ist >> tmp; val = tmp; return ist; }
ostream& operator<<(ostream& ost, __int128 val) { LL tmp = val; ost << tmp; return ost; }
#endif

const int MX = 2000;
using Bits = bitset<MX>;
int n;

void print(Bits a) {
	REM(i, 0, n) {
		cout << a[i];
	}
}

MMInt dl[2000];
MMInt dr[2000];
int sub(Bits a, Bits b) {
	Fill(dl, INF);
	Fill(dr, INF);
	REP(i, 0, n) {
		if (b[i]) {
			dl[i] = 0;
			dr[i] = 0;
		}
	}

	REP(z, 0, 2) {
		dl[0] &= dl[n - 1] + 1;
		REP(i, 1, n) {
			dl[i] &= dl[i - 1] + 1;
		}
	}

	REP(z, 0, 2) {
		dr[n - 1] &= dr[0] + 1;
		REM(i, 1, n) {
			dr[i - 1] &= dr[i] + 1;
		}
	}

	vector<PP> v;
	REP(i, 0, n) {
		if (a[i]) {
			v.push_back(PP(dl[i], dr[i]));
		}
	}
	v.push_back(PP(0, INF));
	v.push_back(PP(INF, 0));
	sort(v);

	vector<PP> w;
	for (PP q : v) {
		while (true) {
			if (w.empty()) break;
			auto p = w.back();
			if (p.second > q.second) break;
			w.pop_back();
		}
		w.push_back(q);
	}

	MMInt mn = INF;
	REP(i, 1, w.size()) {
		PP p = w[i - 1];
		PP q = w[i];
		mn &= 2 * (p.first + q.second);
	}
	return mn;
}

int main() {
	string s = Next<string>();
	string t = Next<string>();
	n = s.size();
	Bits a(s);
	Bits b(t);

	MMInt mn = INF;
	{
		Bits cur = b;
		Bits par;
		REP(i, 0, n) {
			par |= cur;
			mn &= sub(a ^ cur, par) + (a ^ cur).count() + i;
			bool tmp = cur[n - 1];
			cur <<= 1;
			cur[0] = tmp;
			if (n < MX) cur[n] = false;
		}
	}
	{
		Bits cur = b;
		Bits par;
		REP(i, 0, n) {
			par |= cur;
			mn &= sub(a ^ cur, par) + (a ^ cur).count() + i;
			bool tmp = cur[0];
			cur >>= 1;
			cur[n - 1] = tmp;
		}
	}
	cout << (mn == INF ? -1 : (int)mn) << endl;
	return 0;
}




Measured memory_bytes: 3628