//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <stack>
#include <queue>
#include <bitset>
#include <numeric>
#include <cassert>
#include <memory>
#include <random>
#include <functional>
#include <complex>
#include <immintrin.h>
#ifdef DEBUG
#include "./Lib/debug_VC.hpp"
#include "./Lib/Timer.hpp"
#include "./Lib/sample.hpp"
#else
#define dump(...)
#endif

/* macro */
#define FOR(i, b, e) for(ll i = (ll)(b); i < (ll)(e); ++i)
#define RFOR(i, b, e) for(ll i = (ll)(e-1); i >= (ll)(b); --i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REPC(x,c) for(const auto& x:(c))
#define REPI2(it,b,e) for(auto it = (b); it != (e); ++it)
#define REPI(it,c) REPI2(it, (c).begin(), (c).end())
#define RREPI(it,c) REPI2(it, (c).rbegin(), (c).rend())
#define REPI_ERACE2(it, b, e) for(auto it = (b); it != (e);)
#define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end())
#define ALL(x) (x).begin(),(x).end()
#define cauto const auto&
/* macro func */
template<class T>
inline auto sort(T& t) { std::sort(ALL(t)); }
template<class T>
inline auto rsort(T& t) { std::sort((t).rbegin(), (t).rend()); }
template<class T>
inline auto unique(T& t) { (t).erase(unique((t).begin(), (t).end()), (t).end()); }
template<class T, class S>
inline auto chmax(T& t, const S& s) { if (s > t) { t = s; return true; } return false; }
template<class T, class S>
inline auto chmin(T& t, const S& s) { if (s < t) { t = s; return true; } return false; }
inline auto BR() { std::cout << "\n"; }

/* type define */
using ll = long long;
using PAIR = std::pair<ll, ll>;
using VS = std::vector<std::string>;
using VL = std::vector<long long>;
using VVL = std::vector<VL>;
using VVVL = std::vector<VVL>;
using VD = std::vector<double>;
template<class T>
using V = std::vector<T>;

/* using std */
using std::cout;
constexpr char endl = '\n';
using std::cin;
using std::pair;
using std::string;
using std::stack;
using std::queue;
using std::vector;
using std::list;
using std::map;
using std::unordered_map;
using std::multimap;
using std::unordered_multimap;
using std::set;
using std::unordered_set;
using std::unordered_multiset;
using std::multiset;
using std::bitset;
using std::priority_queue;

/* Initial processing  */
struct Preprocessing { Preprocessing() { std::cin.tie(0); std::ios::sync_with_stdio(0); }; }_Preprocessing;

/* Remove the source of the bug */
signed pow(signed, signed) { assert(false); return -1; }

/* define hash */
namespace std {
template <>	class hash<std::pair<ll, ll>> { public:	size_t operator()(const std::pair<ll, ll>& x) const { return hash<ll>()(1000000000 * x.first + x.second); } };
}

/* input */
template<class T> std::istream& operator >> (std::istream& is, vector<T>& vec) { for (T& x : vec) is >> x; return is; }

/* constant value */
constexpr ll MOD = 1000000007;
//constexpr ll MOD = 998244353;

//=============================================================================================;

auto solveR(const string& a, const string& b) {
	ll n = a.size();
	{
		bool one = false;
		REPC(c, b) { one |= (c == '1'); }
		if (!one) { return (a == b) ? 0LL : -1; }
	}
	V<V<bool>> dp(n, V<bool>(n));
	REP(i, n) {
		dp[i][i] = (b[i] == '1');
		FOR(j, i + 1, n) {
			dp[i][j] = (dp[i][j - 1] | (b[j] == '1'));
		}
	}
	auto get = [&](ll l, ll r)->bool {
		if (r < n) { return dp[l][r]; }
		return (dp[l][n - 1] | dp[0][r - n]);
	};

	VL rev; rev.reserve(n);
	REP(i, n)if (b[i] == '1') { rev.emplace_back(i); }

	ll ans = 1e18;
	REP(r, n) {
		V<PAIR> mnrev; mnrev.reserve(n);
		ll tmp = r;
		REP(i, n)if (a[i] != b[(i + r) % n]) {
			++tmp;
			if (get(i, i + r)) { continue; }
			auto itrr = std::upper_bound(ALL(rev), i + r);
			auto revr = ((itrr == rev.end()) ? rev[0] + n : *itrr) - i - r;
			auto itrl = std::lower_bound(ALL(rev), i);
			auto revl = i - ((itrl == rev.begin()) ? rev.back() - n : *(--itrr));
			mnrev.emplace_back(revl, revr);
		}
		if (mnrev.empty()) { chmin(ans, tmp); continue; }
		ll revSize = mnrev.size();
		{

			sort(mnrev);
			VL rmx(revSize, mnrev[revSize - 1].second);
			RREP(i, revSize - 1) { rmx[i] = std::max(rmx[i + 1], mnrev[i].second); }
			chmin(ans, tmp + 2 * rmx[0]);
			REP(i, revSize - 1) {
				chmin(ans, tmp + mnrev[i].first * 2 + 2 * rmx[i + 1]);
			}
		}
		{
			std::sort(ALL(mnrev), [](cauto a, cauto b) {
				if (a.second == b.second) { return a.first < b.first; }
				return a.second > b.second;
			});
			VL lmx(revSize, mnrev[0].first);
			FOR(i, 1, revSize) { lmx[i] = std::max(lmx[i - 1], mnrev[i].first); }
			chmin(ans, tmp + 2 * lmx.back());
			FOR(i, 1, revSize) {
				chmin(ans, tmp + mnrev[i].second * 2 + 2 * lmx[i - 1]);
			}
		}
	}

	return ans;

}

auto solve(const string& a, const string& b) {
	ll ans = solveR(a, b);
	string s = a, t = b;
	std::reverse(ALL(s));
	std::reverse(ALL(t));
	chmin(ans, solveR(s, t));
	return ans;
}

signed main() {
	string a, b;
	cin >> a >> b;

	auto ans = solve(a, b);
	cout << ans << endl;
}

Measured memory_bytes: 908