#include <bits/stdc++.h>

using namespace std;
using ll = long long;
// #define int ll
using PII = pair<ll, ll>;

#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()

template<typename T> T &chmin(T &a, const T &b) { return a = min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = max(a, b); }
template<typename T> bool IN(T a, T b, T x) { return a<=x&&x<b; }
template<typename T> T ceil(T a, T b) { return a/b + !!(a%b); }

template<typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) {
    return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type
fill_v(T &t, const V &v) { t=v; }
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type
fill_v(T &t, const V &v ) { for(auto &e:t) fill_v(e,v); }

template<class S,class T>
ostream &operator <<(ostream& out,const pair<S,T>& a){
    out<<'('<<a.first<<','<<a.second<<')'; return out;
}
template<typename T>
istream& operator >> (istream& is, vector<T>& vec){
    for(T& x: vec) {is >> x;} return is;
}
template<class T>
ostream &operator <<(ostream& out,const vector<T>& a){
    out<<'['; for(T i: a) {out<<i<<',';} out<<']'; return out;
}

int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0}; // DRUL
const int INF = 1<<30;
const ll LLINF = 1LL<<60;
const ll MOD = 1000000007;

ll solve(string a, string b) {
    const ll n = a.size();
    ll ans = LLINF;
    
    // 左(右)にi回shiftしたときの状態
    vector<string> left(n), right(n);
    left[0] = right[0] = b;
    FOR(i, 1, n) {
        left[i] = left[i-1];
        right[i] = right[i-1];
        REP(j, n-1) {
            if(left[i-1][j+1]=='1') left[i][j] = '1';
            if(right[i-1][j]=='1') right[i][j+1] = '1';
        }
        if(left[i-1][0]=='1') left[i][n-1] = '1';
        if(right[i-1][n-1]=='1') right[i][0] = '1';
    }
    // REP(i, n) cout << left[i] << endl;
    // cout << "-----" << endl;
    // REP(i, n) cout << right[i] << endl;
    // cout << endl;
    
    // 左(右)にi回shiftしたときのflip回数
    vector<ll> flip_l(n), flip_r(n);
    string s = b;
    REP(i, n) {
        REP(j, n) if(a[j]!=s[j]) flip_l[i]++;
        char c = s[0];
        FOR(j, 1, n) s[j-1] = s[j];
        s[n-1] = c;
    }
    s = b;
    REP(i, n) {
        REP(j, n) if(a[j]!=s[j]) flip_r[i]++;
        char c = s.back();
        for(ll j=n-2; j>=0; --j) s[j+1] = s[j];
        s[0] = c;
    }    
    // cout << flip_l << endl << flip_r << endl << endl;

    // flip回数-iの累積minを取る
    vector<ll> rui_l(n, LLINF), rui_r(n, LLINF);
    REP(i, n) {
        if(i) rui_r[i] = rui_r[i-1];
        chmin(rui_r[i], flip_r[i] - i);
        if(i) rui_l[i] = rui_l[i-1];
        chmin(rui_l[i], flip_l[i] - i);
    }
    // cout << rui_l << endl << rui_r << endl;

    // 左にx回shiftした
    REP(x, n) {
        ll lb=-1, ub=n;
        while(ub-lb>1) {
            ll mid = (lb+ub)/2;
            auto check = [&](ll mid) {
                // 左にx回shift、右にmid回shiftしたときflip条件満たすか
                REP(i, n) {
                    if(a[i]!='1') continue;
                    if(left[x][i]!='1' && right[mid][i]!='1') {
                        return false;
                    }
                }
                return true;
            };
            if(check(mid)) ub = mid;
            else lb = mid;
        }
        if(ub == n) continue;
        if(ub!=0) chmin(ans, 2*x+2*ub+rui_r[ub]);
        else chmin(ans, x+flip_l[x]);
        FOR(i, ub+1, n) chmin(ans, 2*x+i+flip_r[i]);
    }
    return ans;
}

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

    string a, b;
    cin >> a >> b;

    ll ans = solve(a, b);
    reverse(ALL(a)); reverse(ALL(b));
    chmin(ans, solve(a, b));
    
    if(ans == LLINF) cout << -1 << endl;
    else cout << ans << endl;

    return 0;
}


Measured memory_bytes: 10332