#include <bits/stdc++.h>
#include <sys/time.h>
using namespace std;

#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
#define repi(i,a,b) for(long long i = (long long)(a); i < (long long)(b); i++)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define mt make_tuple
#define mp make_pair
#define ZERO(a) memset(a,0,sizeof(a))
template<class T1, class T2> bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
#define exists find_if
#define forall all_of

using ll = long long; using vll = vector<ll>; using vvll = vector<vll>; using P = pair<ll, ll>;
using ld = long double;  using vld = vector<ld>; 
using vi = vector<int>; using vvi = vector<vi>; vll conv(vi& v) { vll r(v.size()); rep(i, v.size()) r[i] = v[i]; return r; }

inline void input(int &v){ v=0;char c=0;int p=1; while(c<'0' || c>'9'){if(c=='-')p=-1;c=getchar();} while(c>='0' && c<='9'){v=(v<<3)+(v<<1)+c-'0';c=getchar();} v*=p; }
template <typename T, typename U> ostream &operator<<(ostream &o, const pair<T, U> &v) {  o << "(" << v.first << ", " << v.second << ")"; return o; }
template<size_t...> struct seq{}; template<size_t N, size_t... Is> struct gen_seq : gen_seq<N-1, N-1, Is...>{}; template<size_t... Is> struct gen_seq<0, Is...> : seq<Is...>{};
template<class Ch, class Tr, class Tuple, size_t... Is>
void print_tuple(basic_ostream<Ch,Tr>& os, Tuple const& t, seq<Is...>){ using s = int[]; (void)s{0, (void(os << (Is == 0? "" : ", ") << get<Is>(t)), 0)...}; }
template<class Ch, class Tr, class... Args> 
auto operator<<(basic_ostream<Ch, Tr>& os, tuple<Args...> const& t) -> basic_ostream<Ch, Tr>& { os << "("; print_tuple(os, t, gen_seq<sizeof...(Args)>()); return os << ")"; }
ostream &operator<<(ostream &o, const vvll &v) { rep(i, v.size()) { rep(j, v[i].size()) o << v[i][j] << " "; o << endl; } return o; }
template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '['; rep(i, v.size()) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]";  return o; }
template <typename T>  ostream &operator<<(ostream &o, const set<T> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T>  ostream &operator<<(ostream &o, const unordered_set<T> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T, typename U>  ostream &operator<<(ostream &o, const map<T, U> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T, typename U, typename V>  ostream &operator<<(ostream &o, const unordered_map<T, U, V> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it; o << "]";  return o; }
vector<int> range(const int x, const int y) { vector<int> v(y - x + 1); iota(v.begin(), v.end(), x); return v; }
template <typename T> istream& operator>>(istream& i, vector<T>& o) { rep(j, o.size()) i >> o[j]; return i;}
string bits_to_string(ll input, ll n=64) { string s; rep(i, n) s += '0' + !!(input & (1ll << i)); reverse(all(s)); return s; }
template <typename T> ostream &operator<<(ostream &o, const priority_queue<T> &v) { auto tmp = v; while (tmp.size()) { auto x = tmp.top(); tmp.pop(); o << x << " ";} o << endl; return o; }

template <typename T> unordered_map<T, ll> counter(vector<T> vec){unordered_map<T, ll> ret; for (auto&& x : vec) ret[x]++; return ret;};
string substr(string s, P x) {return s.substr(x.fi, x.se - x.fi); }
void vizGraph(vvll& g, int mode = 0, string filename = "out.png") { ofstream ofs("./out.dot"); ofs << "digraph graph_name {" << endl; set<P> memo; rep(i, g.size())  rep(j, g[i].size()) { if (mode && (memo.count(P(i, g[i][j])) || memo.count(P(g[i][j], i)))) continue; memo.insert(P(i, g[i][j])); ofs << "    " << i << " -> " << g[i][j] << (mode ? " [arrowhead = none]" : "")<< endl;  } ofs << "}" << endl; ofs.close(); system(((string)"dot -T png out.dot >" + filename).c_str()); }

size_t random_seed; namespace std { using argument_type = P; template<> struct hash<argument_type> { size_t operator()(argument_type const& x) const { size_t seed = random_seed; seed ^= hash<ll>{}(x.fi); seed ^= (hash<ll>{}(x.se) << 1); return seed; } }; }; // hash for various class
namespace myhash{ const int Bsizes[]={3,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77,81}; const int xor_nums[]={0x100007d1,0x5ff049c9,0x14560859,0x07087fef,0x3e277d49,0x4dba1f17,0x709c5988,0x05904258,0x1aa71872,0x238819b3,0x7b002bb7,0x1cf91302,0x0012290a,0x1083576b,0x76473e49,0x3d86295b,0x20536814,0x08634f4d,0x115405e8,0x0e6359f2}; const int hash_key=xor_nums[rand()%20]; const int mod_key=xor_nums[rand()%20]; template <typename T> struct myhash{ std::size_t operator()(const T& val) const { return (hash<T>{}(val)%mod_key)^hash_key; } }; };
template <typename T> class uset:public std::unordered_set<T,myhash::myhash<T>> { using SET=std::unordered_set<T,myhash::myhash<T>>; public: uset():SET(){SET::rehash(myhash::Bsizes[rand()%20]);} };
uint32_t randxor() { static uint32_t x=1+(uint32_t)random_seed,y=362436069,z=521288629,w=88675123; uint32_t t; t=(x^(x<<11));x=y;y=z;z=w; return( w=(w^(w>>19))^(t^(t>>8)) ); }
struct timeval start; double sec() { struct timeval tv; gettimeofday(&tv, NULL); return (tv.tv_sec - start.tv_sec) + (tv.tv_usec - start.tv_usec) * 1e-6; }
struct init_{init_(){ gettimeofday(&start, NULL); ios::sync_with_stdio(false); cin.tie(0); struct timeval myTime; struct tm *time_st; gettimeofday(&myTime, NULL); time_st = localtime(&myTime.tv_sec); srand(myTime.tv_usec); random_seed = RAND_MAX / 2 + rand() / 2; }} init__;
#define rand randxor

static const double EPS = 1e-14;
static const long long INF = 1e18;
static const long long mo = 1e9+7;
#define ldout fixed << setprecision(40) 

string a, b;
vll bs;
ll n;
vll rpos, lpos;
void constructPos(void) {
    repi(i, 1, 6*n) {
        chmin(lpos[i%n], b[i%n] == '1' ? 0 : lpos[(i-1)%n] + 1);
    }
    for (ll i = 6*n; i>=1; i--) {
        chmin(rpos[i%n], b[i%n] == '1' ? 0 : rpos[(i+1)%n] + 1);
    }
}
// 右にd回移動する時、何回移動しなければならないか
ll calc(ll d) {
//    cout << "#############"<<endl;
//    cout << d << endl;
    ll flips = 0;
    vector<P> lr;
    rep(i, n) {
        if (a[i] != b[i+d]) {
            flips++;
            // b[i, i+d]に1がないといけない
            // b[i, i+d+1)に1がないといけない
            if (bs[i+d+1] - bs[i]) {
                // 1があるのでどうでもいい
                continue;
            } else {
//                cout << i << "#HIT"<<endl;
                // 1がないので左右どちらかに寄り道しないといけない
                lr.pb(P(lpos[i], rpos[(i+d)%n])); // TODO 逆？
//                cout << i << " " << lr.back() << endl;
            }
        }
    }
    if (!lr.size()) {
        return d + flips;
    }

    sort(all(lr));
    vll rmax(lr.size()+1, -INF); // max r[i, r.size())
    for (ll i = lr.size()-1; i >= 0; i--) {
//        cout << rmax[i+1] << " " << lr[i].se<<endl;
        rmax[i] = max(rmax[i+1], lr[i].se);
    }
//n    cout << lr << " " << rmax << endl;

    ll ret = INF;
    rep(i, lr.size()+1) {
        if (!i) 
            chmin(ret, rmax[0]);
        else if (i == lr.size())
            chmin(ret, lr[lr.size()-1].fi);
        else
            chmin(ret, lr[i-1].fi + rmax[i]);
    }
//    cout << d  << " " << flips << " " << ret  << " #ret" <<endl;
    if (d+flips+ret*2 == 34) {
//        cout << "HOGE!!!!!!!!!!!!!!!!" << endl;
    }

    return d + flips + ret * 2;
}
ll solve(void) {
    rpos = vll(n, INF);
    lpos = vll(n, INF);
    bs = vll(b.size()+1);
    rep(i, b.size()) {
////        cout << bs[i] << " " << b[i]  << endl;
        bs[i+1] = bs[i] + b[i] - '0'; 
    }
//    cout << bs << "BS"<< endl;
    /*
    cout << bs << endl;
    cout << a << endl;
    cout << b << endl;
    */

    ll ret = INF;
    constructPos();
//    cout << rpos << endl;
//    cout << lpos << endl;
    rep(i, rpos.size()) { assert(rpos[i] != INF); }
    rep(i, lpos.size()) { assert(lpos[i] != INF); }
    rep(d, 2*n) chmin(ret, calc(d));

    return ret;
}
int main(void) {
    cin >> a >> b;
    n = a.size();
    ll af = 1, bf = 1;
    rep(i, n) af &= a[i] == '0', bf &= b[i] == '0';
//    cout << af << " " << bf << endl;
    if (bf == 1) {
        if (af == 1) {
            cout << 0 << endl;
        } else {
            cout << -1 << endl;
        }
        return 0;
    }

    a += a;
    a += a;
    b += b;
    b += b;

    ll ret = INF;
    chmin(ret, solve());
    reverse(all(a));
    reverse(all(b));
    chmin(ret, solve());
    
    cout << ret << endl;

    return 0;
}


Measured memory_bytes: 508