#include <bits/stdc++.h>
#include <random>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef double ld;
//#define ll __int128
//#define int ll
//#define int ll
//#define char ll
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<vvc> vvvc;
typedef pair<int, int> pii;
typedef pair<pii, pii> piii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii> vpi;
typedef vector< vi > vvi;
typedef vector< vvi > vvvi;
typedef vector<short> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<ld> vld;
typedef vector<vld> vvld;
typedef vector<vvld> vvvld;
typedef vector<string> vst;
typedef vector<vst> vvst;
typedef pair<ld, ld> pld;

#define inmin(a, b) a = min(a, (b))
#define inmax(a, b) a = max(a, (b))
#define ALL(a) a.begin(),a.end()
#define RALL(a) a.rbegin(),a.rend()
#define sqr(x) ((x) * (x))
#define fori(i, n) for(int i = 0; i < int(n); ++i)
#define SZ(a) ((int)((a).size()))
#define triple(T) tuple<T, T, T>
#define quad(T) tuple<T, T, T, T>
#define watch(x) cerr << (#x) << " = " << (x) << endl;

#ifdef MAX_HOME
#define cerr cout
#else
#define cerr if (false) cerr
#endif

const double PI = 2 * acos(0.0);
#define rand shittttty_shit
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng_64(chrono::steady_clock::now().time_since_epoch().count());

const string DIGITS = "0123456789";
const string ALPH = "abcdefghijklmnopqrstuvwxyz";


template <class T0, class T1>
inline ostream & operator << (ostream &out, pair<T0, T1> &a) {
    return out << "{" << a.first << ", " << a.second << "}";
}

template <class T0, class T1>
inline istream & operator >> (istream &in, pair<T0, T1> &a) {
    return in >> a.first >> a.second;
}

template <class T0, class T1, class T2>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << "}";
}

template <class T0, class T1, class T2, class T3>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2, T3> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << ", " <<  get<3>(a) << "}";
}

template<class T>
inline ostream & operator << (ostream &out, vector<T> &a) {
    out << "[";
    fori (i, a.size())
        out << a[i] << vector<string>{", ", "]  "}[i + 1 == a.size()];
    return out;
}


void smain();



signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

#ifdef MAX_HOME
    freopen("input.txt", "r", stdin);
    clock_t start = clock();
#endif
    cout << setprecision(4) << fixed;
    smain();
#ifdef MAX_HOME
    cout << "\n\n\n\nTOTAL EXECUTION TIME: " << float( clock () - start ) /  CLOCKS_PER_SEC << endl;
#endif
    return 0;
}

const int N = 4020;
const int MID = 2010;
int lf[N], rf[N];

vector<pii> points[N];
int ans[N];

int pref[N];
int n;

int get(int l, int r) { // TODO
    if (r < l)
        r += n;
    return pref[r] - (l ? pref[l - 1] : 0);
}

void smain() {
    string s, t;
    cin >> s >> t;
    if (s == t) {
        cout << "0";
        return;
    }
    n = s.size();
    vi a(n), b(n);
    fori (i, n) {
        a[i] = s[i] == '1';
        b[i] = t[i] == '1';
        pref[i] = b[i];
        if (i)
            pref[i] += pref[i - 1];
    }
    for (int i = n; i < 2 * n; ++i) {
        pref[i] = b[i - n];
        pref[i] += pref[i - 1];
    }
    if (count(ALL(b), 1) == 0) {
        cout << "-1\n";
        return;
    }
    int r = 0;
    fori (i, n) {
        if (b[i])
            r = i;
    }

    int l = 0;
    for (int i = n - 1; i >= 0; --i) {
        if (b[i])
            l = i;
    }

    lf[0] = b[0] ? 0 : n - r;

    for (int i = 1; i < n; ++i) {
        lf[i] = lf[i - 1] + 1;
        if (b[i])
            lf[i] = 0;
    }

    rf[n - 1] = b[n - 1] ? 0 : l + 1;

    for (int i = n - 2; i >= 0; --i) {
        rf[i] = rf[i + 1] + 1;
        if (b[i])
            rf[i] = 0;
    }


    for (int x = 0; x < n; ++x) {
        for (int s = -n + 1; s < n; ++s) {
            int nx = (x + s + n) % n;
            int lcur, rcur;
            int cur = 0;
            lcur = rcur = 0;
            if (a[x] == 0) {
                if (b[nx] == 1) {
                    cur++;
                }
            } else {
                if (b[nx] == 0) {
                    cur++;
                    if (s >= 0) {
                        if (!get(x, nx)) {
                            lcur = lf[x];
                            rcur = rf[nx];
                        }
                    } else {
                        if (!get(nx, x)) {
                            lcur = rf[x];
                            rcur = lf[nx];
                        }
                    }
                }
            }

            points[s + MID].push_back({lcur, rcur});

            ans[s + MID] += cur;
        }
    }

    int res = n * 10;

    for (int s = -n + 1; s < n; ++s) {
        sort(ALL(points[s + MID]));
        vi sufmax(n, 0);
        sufmax.back() = points[s + MID].back().second;
        for (int i = n - 2; i >= 0; --i) {
            sufmax[i] = max(points[s + MID][i].second, sufmax[i + 1]);
        }
        int bs = sufmax[0];
        for (int i = 0; i < n; ++i) {
            int cur = points[s + MID][i].first + (i < n - 1 ?  sufmax[i + 1] : 0);
            inmin(bs, cur);
        }
        inmin(res, bs * 2 + ans[s + MID] + abs(s));
    }
    cout << res;
}

Measured memory_bytes: 64640