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

#define endl '\n'
#define ALL(a)  (a).begin(),(a).end()
#define ALLR(a)  (a).rbegin(),(a).rend()
#define spa << " " <<
#define test cout<<"test"<<endl;
#define fi first
#define se second
#define MP make_pair
#define PB push_back
#define EB emplace_back
#define rep(i,n,m) for(ll i = (n); i < (ll)(m); i++)
#define rrep(i,n,m) for(ll i = (m) - 1; i >= (ll)(n); i--)
using ll = long long;
using ld = long double;
const ll MOD = 1e9+7;
//const ll MOD = 998244353;
const ll INF = 1e18;
using P = pair<ll, ll>;
template<typename T>
void chmin(T &a,T b){if(a>b)a=b;}
template<typename T>
void chmax(T &a,T b){if(a<b)a=b;}
void pmod(ll &a,ll b){a=(a+b)%MOD;}
void pmod(ll &a,ll b,ll c){a=(b+c)%MOD;}
void qmod(ll &a,ll b){a=(a*b)%MOD;}
void qmod(ll &a,ll b,ll c){a=(b*c)%MOD;}
ll median(ll a,ll b, ll c){return a+b+c-max({a,b,c})-min({a,b,c});}
void ans1(bool x){if(x) cout<<"Yes"<<endl;else cout<<"No"<<endl;}
void ans2(bool x){if(x) cout<<"YES"<<endl;else cout<<"NO"<<endl;}
void ans3(bool x){if(x) cout<<"Yay!"<<endl;else cout<<":("<<endl;}
template<typename T1,typename T2>
void ans(bool x,T1 y,T2 z){if(x)cout<<y<<endl;else cout<<z<<endl;}  
template<typename T>
void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cout<<v[i][0];for(ll j=1;j<w;j++)cout spa v[i][j];cout<<endl;}};
void debug(vector<string>&v,ll h,ll w){for(ll i=0;i<h;i++)
{for(ll j=0;j<w;j++)cout<<v[i][j];cout<<endl;}};
template<typename T>
void debug(vector<T>&v,ll n){if(n!=0)cout<<v[0];
for(ll i=1;i<n;i++)cout spa v[i];cout<<endl;};
template<typename T>
vector<vector<T>>vec(ll x, ll y, T w){
  vector<vector<T>>v(x,vector<T>(y,w));return v;}
ll gcd(ll x,ll y){ll r;while(y!=0&&(r=x%y)!=0){x=y;y=r;}return y==0?x:y;}
vector<ll>dx={1,0,-1,0,1,1,-1,-1};
vector<ll>dy={0,1,0,-1,1,-1,1,-1};
template<typename T>
vector<T> make_v(size_t a,T b){return vector<T>(a,b);}
template<typename... Ts>
auto make_v(size_t a,Ts... ts){
  return vector<decltype(make_v(ts...))>(a,make_v(ts...));
}
ostream &operator<<(ostream &os, pair<ll, ll>&p){
  return os << p.first << " " << p.second;
}  
int main(){
  cin.tie(nullptr);
  ios_base::sync_with_stdio(false);
  //cout<<fixed<<setprecision(10);
  ll res=0,buf=0;
  bool judge = true;
  string a,b;cin>>a>>b;
  res=INF;
  ll n=a.size();
  vector<ll>l(n,INF),r(n,INF);
  rep(i,0,n){
    rep(j,0,n)if(b[(i+j)%n]=='1')chmin(r[i],j);
    rep(j,0,n)if(b[(i+n-j)%n]=='1')chmin(l[i],j);
  }
  //debug(l,n);
  //debug(r,n);
  rep(i,0,n){
    string s=a;
    judge=true;
    rep(j,0,n)s[(i+j)%n]=a[j];
    if(l[0]==INF){
      if(s==b)chmin(res,min(i,n-i));
      continue;
    }
    ll minbuf=INF;
    vector<P>lp;
    ll cnt=0;
    rep(j,0,n){
      if(s[j]!=b[j])cnt++;
    }
    rep(j,0,n){
      ll pos=(n+j-i)%n;
      if(s[j]!=b[j]&&r[pos]>i)lp.EB(r[pos],n-l[pos]);
    }
    lp.EB(n,n);
    lp.EB(i,i);
    sort(ALL(lp));
    multiset<ll>ls;
    rep(j,1,lp.size())ls.insert(lp[j].se);
    rep(j,0,(ll)lp.size()-1){
      chmin(minbuf,i+(lp[j].fi-i)*2+(n-*ls.begin())*2);
      ls.erase(ls.find(lp[j+1].se));
    }
    vector<P>rp;
    rep(j,0,n){
      ll pos=(n+j-i)%n;
      if(s[j]!=b[j]&&l[pos]>n-i)rp.EB(r[pos],n-l[pos]);
    }
    //rep(j,0,rp.size())cout<<i spa rp[j]<<endl;
    rp.EB(0,0);
    rp.EB(i,i);
    sort(ALL(rp));
    multiset<ll>rs;
    rep(j,1,rp.size())rs.insert(rp[j].se);
    rep(j,0,(ll)rp.size()-1){
      chmin(minbuf,n-i+rp[j].fi*2+(i-*rs.begin())*2);
      rs.erase(rs.find(rp[j+1].se));
    }
    //cout<<i spa minbuf spa cnt<<endl;
    chmin(res,minbuf+cnt);
    chmin(res,cnt+n+min(n-i,i));
  }
  ans(res==INF,-1,res);
  return 0;
}

Measured memory_bytes: 384