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

using namespace std;

#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}


typedef long long ll;
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const ll MOD = 1000000007;
//const ll MOD = 998244353;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { -1,0, 1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
//#define mp make_pair


int solve(string a, string b) {
  int n = a.size();
  
  vi left(n), right(n);
  int last;
  rrep (i, n) {
    if (b[i] == '1') {
      last = i;
      break;
    }
  }
  rep (i, n) {
    if (b[i] == '1') last = i;
    left[i] = (i - last + n) % n;
  }

  rep (i, n) {
    if (b[i] == '1') {
      last = i;
      break;
    }
  }
  rrep (i, n) {
    if (b[i] == '1') last = i;
    right[i] = (last - i + n) % n;
  }

  int ans = inf;
  rep (z, n) {
    set<pii> st1, st2;
    int diff = 0;
    rep (i, n) {
      if (a[i] == b[(i - z + n) % n]) continue;
      diff++;
      if (left[i] > z) {
        st1.insert(pii(right[i], i));
        st2.insert(pii(-left[i], i));
      }
    }

    rep (r, n) {
      while (st1.size() > 0 && st1.begin()->first <= r) {
        int idx = st1.begin()->second;
        st1.erase(st1.begin());
        st2.erase(pii(-left[idx], idx));
      }
      int add = 0;
      if (st2.size() > 0) {
        add = -st2.begin()->first - z;
      }
      chmin(ans, diff + 2*r + z + add * 2);
    }
  }
  return ans;
}


int main() {
  string a, b;
  cin >> a >> b;
  int n = a.size();
  bool all_zero = true;
  rep (i, n) {
    if (b[i] != '0') all_zero = false;
  }
  if (all_zero) {
    if (a == b) {
      cout << 0 << endl;
    }
    else {
      cout << -1 << endl;
    }
    return 0;
  }

  int ans = solve(a, b);
  reverse(all(a));
  reverse(all(b));
  ans = min(ans, solve(a, b));
  cout << ans << endl;
}


Measured memory_bytes: 512