#include<bits/stdc++.h>
//ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
//clock_t start=clock();clock_t end=clock();cout<<(double)(end-start)/CLOCKS_PER_SEC<<endl;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int ui;
typedef pair<int,int> pii;
typedef pair<pii,int> ppii;
typedef pair<int,pii> pipi;
typedef pair<ll,ll> pll;
typedef pair<pll,ll> ppll;
typedef pair<ll,pll> plpl;
typedef tuple<ll,ll,ll> tl;
typedef pair<double,double> pdd;
typedef vector<vector<ll>> mat;
ll mod=1000000007;
ll mod2=998244353;
ll mod3=1000003;
ll mod4=998244853;
ll mod5=1000000009;
ll inf=1LL<<60;
double pi=3.141592653589793238462643383279L;
double eps=1e-14;
#define rep(i,m,n) for(ll i=m;i<n;i++)
#define rrep(i,n,m) for(ll i=n;i>=m;i--)
#define srep(itr,st) for(auto itr=st.begin();itr!=st.end();itr++)
#define mrep(itr,mp) for(auto itr=mp.begin();itr!=mp.end();itr++)
#define Max(a,b) a=max(a,b)
#define Min(a,b) a=min(a,b)
int dh[4]={1,-1,0,0};
int dw[4]={0,0,1,-1};
int ddh[8]={-1,-1,-1,0,0,1,1,1};
int ddw[8]={-1,0,1,-1,1,-1,0,1};
ll gcd(ll a,ll b){
    if(a<b)swap(a,b);
    if(b==0)return a;
    if(a%b==0)return b;
    return gcd(b,a%b);
}
ll Pow(ll n,ll k){
    ll ret=1;
    ll now=n;
    while(k>0){
        if(k&1)ret*=now;
        now*=now;
        k/=2;
    }
    return ret;
}
ll beki(ll n,ll k,ll md){
  ll ret=1;
  ll now=n;
  while(k>0){
    if(k%2==1){
      ret*=now;
      ret%=md;
    }
    now*=now;
    now%=md;
    k/=2;
  }
  return ret;
}
ll gyaku(ll n,ll md){
  return beki(n,md-2,md);
}
ll popcount(ll n){
    ll ret=0;
    ll u=n;
    while(u>0){
        ret+=u%2;
        u/=2;
        
    }
    return ret;
}
struct ST{
private:
    ll n;
    vector<pll> dat;
public:
    ST(vector<ll> v){
        ll sz=v.size();
        n=1;while(n<sz)n*=2;
        pll p={inf,inf};
        dat.resize(2*n-1,p);
        rep(i,0,sz)dat[i+n-1]={v[i],i};
        rrep(i,n-2,0){
            dat[i]=min(dat[i*2+1],dat[i*2+2]);
        }
    }
    void add(ll k,ll x){
        ll i=k+n-1;
        dat[i]={x,k};
        while(i>0){
            i=(i-1)/2;
            dat[i]=min(dat[2*i+1],dat[2*i+2]);
        }
    }
    pll que(ll a,ll b,ll k=0,ll l=0,ll r=-1){
        if(r<0)r=n;
        if(b<=l||a>=r)return {inf,inf};
        if(a<=l&&b>=r)return dat[k];
        pll m1=que(a,b,2*k+1,l,(l+r)/2);
        pll m2=que(a,b,2*k+2,(l+r)/2,r);
        return min(m1,m2);
    }
};
ll dis(ll a,ll b,ll n){
    if(b>=a)return min(b-a,n+a-b);
    else return min(a-b,n+b-a);
}
int main(){
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    string s,t;cin>>s>>t;
    int n=(int)s.size();
    int a[n],b[n];
    int ca=0,cb=0;
    rep(i,0,n){
        a[i]=s[i]-'0';
        b[i]=t[i]-'0';
        ca+=a[i];cb+=b[i];
    }
    if(cb==0){
        if(ca==0)cout<<0<<endl;
        else cout<<-1<<endl;
        return 0;
    }
    int l[n],r[n];
    rep(i,0,n){
        l[i]=0;r[i]=0;
        int now=i;
        while(b[now]==0){
            l[i]--;
            now++;
            now%=n;
        }
        now=i;
        while(b[now]==0){
            r[i]++;
            now--;
            now+=n;
            now%=n;
        }
    }
    ll ans=inf;
    rep(i,0,n){
        vector<ll> v(n),vv(n);
        ll sum=0;
        vector<pll> w,ww;
        rep(j,0,n){
            if(a[j]==0){
                if(b[(j-i+n)%n]==1)sum++;
                v[j]=0;
                vv[j]=0;
            }
            else{
                if(b[(j-i+n)%n]==0){
                    sum++;
                    v[j]=l[j];
                    vv[j]=-r[j];
                    w.push_back({r[j],j});
                    ww.push_back({-l[j],j});
                }
                else{
                    v[j]=0;
                    vv[j]=0;
                }
            }
        }
        ST seg1(v),seg2(vv);
        sort(w.begin(),w.end());
        sort(ww.begin(),ww.end());
        deque<pll> dq,dq2;
        rep(j,0,w.size()){
            dq.push_back(w[j]);
            dq2.push_back(ww[j]);
        }
        /*if(i==2){
            cout<<sum<<endl;
            rep(j,0,w.size())cout<<dq[j].first<<" ";
            cout<<endl;
            rep(j,0,w.size())cout<<dq2[j].first<<" ";
            cout<<endl;
        }*/
        ll mi=inf;
        rep(j,0,n){
            while(dq.size()>0&&dq.front().first==j){
                pll p=dq.front();dq.pop_front();
                seg1.add(p.second,0);
            }
            while(dq2.size()>0&&dq2.front().first==j){
                pll p=dq2.front();dq2.pop_front();
                seg2.add(p.second,0);
            }
            pll p1=seg1.que(0,n);
            if(p1.first==0)Min(mi,sum+j+dis(i,j,n));
            else{
                Min(mi,sum+j+j-p1.first+dis(i,n+p1.first,n));
            }
            //if(i==2)cout<<mi<<" ";
            p1=seg2.que(0,n);
            //if(i==2&&j==0)cout<<p1.first<<endl;
            if(p1.first==0)Min(mi,sum+j+dis(i,(n-j)%n,n));
            else{
                Min(mi,sum+j+j-p1.first+dis(i,-p1.first,n));
            }
            //if(i==2)cout<<mi<<" "<<endl;
        }
        //cout<<mi<<endl;
        Min(ans,mi);
       // cout<<mi<<" ";
    }
    cout<<ans<<endl;
}






Measured memory_bytes: 648