#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("unroll-loops")
//#pragma warning(disable : 4996)

#ifdef _MSC_VER
#include <intrin.h>
#define __builtin_popcount __popcnt
#define __builtin_popcountll __popcnt64
#endif

#include <limits.h>
#include <math.h>
#include <time.h>
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m - 1; i >= n; --i)
#define SORT(v, n) sort(v, v + n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v, n) reverse(v, v + n);
#define VREVERSE(v) reverse(v.begin(), v.end())
#define ll long long
#define print(x) cout << (x) << '\n'
#define pe(x) cout << (x) << " "
#define DEBUG(x) cout << #x << ": " << x << endl
#define lb(v, n) lower_bound(v.begin(), v.end(), (n))
#define ub(v, n) upper_bound(v.begin(), v.end(), (n))
#define int long long
//#define double long double
#define all(x) (x).begin(), (x).end()
#define print_space(v) REP(i, v.size()) cout << v[i] << " \n"[i==(int)v.size()-1]
template <typename T1, typename T2> inline void chmin(T1& a, T2 b) { if (a > b) a = b; }
template <typename T1, typename T2> inline void chmax(T1& a, T2 b) { if (a < b) a = b; }
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
std::random_device rd;
std::mt19937 mt(rd());
constexpr ll MOD = 1e9 + 7;
constexpr int MAX = 500050;
const double pi = acos(-1);
constexpr double EPS = 1e-8;
constexpr ll LINF = 1e18 + 1;
constexpr int INF = 1e9 + 1;
//int dx[4] = { 0,0,-1,1 }, dy[4] = { 1,-1,0,0 };


int slv(string A, string B) {
	int N = A.size();
	ll ans = LINF;
	//DEBUG(A);
	//DEBUG(B);
	B = B + B;
	vector<int>cum(2 * N + 1);
	REP(i, 2 * N) {
		cum[i + 1] = cum[i];
		if (B[i] == '1')cum[i + 1]++;
	}
	vector<int>L(2 * N,N), R(2 * N,N);
	FOR(i, 1, 2 * N) {
		chmin(L[i], L[i - 1]+1);
		if (B[i] == '1')L[i] = 0;
	}
	REPR(i, 2 * N - 1) {
		chmin(R[i], R[i + 1] + 1);
		if (B[i] == '1')R[i] = 0;
	}
	REP(d, N + 1) {
		//DEBUG(d);
		int cnt = 0;
		int res = 0;
		//vector<int>ls, rs;
		vector<vector<int>>rs(N + 1);
		bool found = false;
		REP(i, N) {
			if (A[i] != B[i + d]) {
				cnt++;
				if (cum[i + d + 1] - cum[i] == 0) {
					//ls.push_back(L[i]);
					found = true;
					int dl = min(L[i], L[(i + N % (2 * N))]);
					int dr = min(R[i+d], R[(i + d + N) % (2 * N)]);
					rs[dl].push_back(dr);
				}
			}
		}
		ll admin = 2*N;
		int r = 0;
		if (!found)admin = 0;
		REPR(l, N + 1) {
			chmin(admin, l * 2 + r * 2);
			for (auto x : rs[l])chmax(r, x);
		}
		res = cnt + admin + d;
		chmin(ans, res);
		//DEBUG(res);
	}
	return ans;
}

void solve() {
	string A, B; cin >> A >> B;
	bool found = false;
	for (auto c : B)if (c == '1')found = true;
	if (A != B && !found) {
		print(-1); return;
	}
	ll ans = slv(A, B);
	VREVERSE(A); VREVERSE(B);
	chmin(ans, slv(A, B));
	print(ans);
}



signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	//int q;
	//cin >> q;
	//while (q--)
		solve();

}


Measured memory_bytes: 3828