#pragma region Template
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <queue>
#include <vector>
#include <map>
#include <cmath>
#include <string>
#include <cstring>
#include <utility>
#include <stack>
#include <set>
#include <algorithm>
#include <bitset>
#include <functional>
#include <ctime>
#include <cassert>
#include <valarray>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <complex>
#include <regex>
#include <numeric>
#pragma comment(linker, "/STACK:167772160")

using namespace std;
#define mp make_pair
#ifdef LOCAL
#define eprintf(...) fprintf(stderr, __VA_ARGS__)
#define print_var(x) cerr << #x << " : " << (x) << endl
#define print_array(arr, len) {cerr << #arr << " : "; for(int i = 0; i < len; ++i) cerr << arr[i] << ' '; cerr << endl;}
#define print_2d_array(arr, len1, len2) {cerr << #arr << endl; for(int i = 0; i < len1; ++i, cerr << endl) for(int j = 0; j < len2; ++j) cerr << arr[i][j] << ' ';}
#define print_iterable(i) {cerr << #i << " : "; for(auto e : i) cerr << e << ' '; cerr << endl;}
#define print_new_line() cerr << endl

template <typename T, typename Q>
void print_pair1(pair<T, Q> x)
{
	cerr << "(" << x.first << ", " << x.second << ")\n";
}

#define print_pair(x) {cerr << #x << " : "; print_pair1(x);}
#else
#define print_pair(x) (void)0
#define eprintf(...) (void)0
#define print_var(x) (void)0
#define print_array(arr, len) {}
#define print_2d_array(arr, len1, len2) {}
#define print_iterable(i) {}
#define print_new_line() (void)0
#endif

#define rand govno_ebanoe

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef pair<int, int> pii;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;

const int INF = (int)1e9 + 10;
const ll LINF = ll(2e18) + 10;
const double PI = acosl(-1);
const double eps = 1e-8;
const ld EPS = 1e-12;
#pragma endregion

#ifdef LOCAL
#define ERR_CATCH
//#define NOERR
#endif

const int N = 6010;
int n;
string a, b;
char buf[N];
int ps[N];
int to_l[N], to_r[N];
int smax[N];

string read()
{
	scanf("%s", buf);
	return buf;
}

void solve()
{
	a = read();
	b = read();
	if (a == b)
	{
		puts("0");
		return;
	}
	n = a.size();
	bool oneb = false;
	for (auto& e : a)
		e -= '0';
	for (auto& e : b)
	{
		e -= '0';
		if (e)
			oneb = true;
	}
	if (!oneb)
	{
		puts("-1");
		return;
	}
	int res = 10 * n;
	b = b + b + b;
	partial_sum(b.begin(), b.end(), ps);
	for(int i = n; i < 2 * n; ++i)
	{
		int x = i;
		while (!b[x])
			--x;
		to_l[i] = i - x;
		x = i;
		while (!b[x])
			++x;
		to_r[i] = x - i;
	}
	copy(to_l + n, to_l + 2 * n, to_l);
	copy(to_l + n, to_l + 2 * n, to_l + 2 * n);
	copy(to_r + n, to_r + 2 * n, to_r);
	copy(to_r + n, to_r + 2 * n, to_r + 2 * n);
	for(int sh = -n + 1; sh <= n - 1; ++sh)
	{
		auto tres = abs(sh);
		vector<pii> go;
		for(int i = 0; i < n; ++i)
			if (a[i] != b[i + n + sh])
			{
				++tres;
				auto f = (i + n);
				auto s = (i + n + sh);
				if (f > s)
					swap(f, s);
				if (ps[s] - ps[f - 1] == 0) // no ones
					go.emplace_back(to_l[f], to_r[s]);
			}
		if (go.size() > 0)
		{
			sort(go.begin(), go.end());
			smax[go.size()] = 0;
			for (int i = (int)go.size() - 1; i >= 0; --i)
				smax[i] = max(smax[i + 1], go[i].second);
			int add = smax[0];
			for (int i = 0; i < go.size(); ++i)
				add = min(add, go[i].first + smax[i + 1]);
			tres += 2 * add;
		}
		res = min(res, tres);
	}
	printf("%d\n", res);
}

int main()
{
#ifdef LOCAL
	freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
#ifdef NOERR
	freopen("err.txt", "w", stderr);
#endif
#else
	//freopen("knight.in", "r", stdin);
	//freopen("knight.out", "w", stdout);
#endif

#ifdef ERR_CATCH
	try
	{
#endif

#ifdef ST
		while (true)
			solve();
#endif
#ifdef CASES
#define MULTITEST
#endif
#ifdef MULTITEST
		int t;
		scanf("%d", &t);
		char endl1[5];
		fgets(endl1, 5, stdin);
		for (int i = 0; i < t; ++i)
		{
#ifdef CASES
			printf("Case #%d: ", i + 1);
#endif
			solve();
#ifdef CASES
			eprintf("Passed case #%d:\n", i + 1);
#endif
		}
#else
		solve();
#endif

#ifdef ERR_CATCH
	}
	catch (logic_error e)
	{
		print_var(e.what());
		puts("___________________________________________________________________________");
		exit(0);
	}
#endif
#ifdef LOCAL
	eprintf("\n\nTime: %.3lf\n", double(clock()) / CLOCKS_PER_SEC);
#endif
}

Measured memory_bytes: 384