#include <bits/stdc++.h>
#define MP make_pair
#define PB push_back
#define int long long
#define st first
#define nd second
#define rd third
#define FOR(i, a, b) for(int i =(a); i <=(b); ++i)
#define RE(i, n) FOR(i, 1, n)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define REP(i, n) for(int i = 0;i <(n); ++i)
#define VAR(v, i) __typeof(i) v=(i)
#define FORE(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
using namespace std;
template<typename TH> void _dbg(const char* sdbg, TH h) { cerr<<sdbg<<"="<<h<<"\n"; }
template<typename TH, typename... TA> void _dbg(const char* sdbg, TH h, TA... t) {
  while(*sdbg != ',')cerr<<*sdbg++; cerr<<"="<<h<<","; _dbg(sdbg+1, t...);
}
#ifdef LOCAL
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#define debugv(x) {{cerr <<#x <<" = "; FORE(itt, (x)) cerr <<*itt <<", "; cerr <<"\n"; }}
#else
#define debug(...) (__VA_ARGS__)
#define debugv(x)
#define cerr if(0)cout
#endif
#define next ____next
#define prev ____prev
#define left ____left
#define hash ____hash
typedef long long ll;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<ll> VLL;
typedef vector<pair<int, int> > VPII;
typedef vector<pair<ll, ll> > VPLL;

template<class C> void mini(C&a4, C b4){a4=min(a4, b4); }
template<class C> void maxi(C&a4, C b4){a4=max(a4, b4); }
template<class T1, class T2>
ostream& operator<< (ostream &out, pair<T1, T2> pair) { return out << "(" << pair.first << ", " << pair.second << ")";}
template<class A, class B, class C> struct Triple { A first; B second; C third;
  bool operator<(const Triple& t) const { if (st != t.st) return st < t.st; if (nd != t.nd) return nd < t.nd; return rd < t.rd; } };
template<class T> void ResizeVec(T&, vector<int>) {}
template<class T> void ResizeVec(vector<T>& vec, vector<int> sz) {
  vec.resize(sz[0]); sz.erase(sz.begin()); if (sz.empty()) { return; }
  for (T& v : vec) { ResizeVec(v, sz); }
}
typedef Triple<int, int, int> TIII;
template<class A, class B, class C>
ostream& operator<< (ostream &out, Triple<A, B, C> t) { return out << "(" << t.st << ", " << t.nd << ", " << t.rd << ")"; }
template<class T> ostream& operator<<(ostream& out, vector<T> vec) { out<<"("; for (auto& v: vec) out<<v<<", "; return out<<")"; }

    
int32_t main() {

  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(10);
  cerr << fixed << setprecision(10);
  cin.tie(0);
  //double beg_clock = 1.0 * clock() / CLOCKS_PER_SEC;
  
  string s1, s2;
  cin>>s1>>s2;
  if (s1 == s2) {
    cout<<"0"<<endl;
    return 0;
  }
  if (s2 == string(SZ(s2), '0')) {
    cout<<"-1"<<endl;
    return 0;
  }
  int n = SZ(s1);
  VI left(n), right(n);
  REP (tr, 3) {
    REP (i, n) {
      if (s2[i] == '1') {
        left[i] = 0;
      } else {
        left[i] = 1 + left[(i + n - 1) % n];
      }
    }
    FORD (i, n - 1, 0) {
      if (s2[i] == '1') {
        right[i] = 0;
      } else {
        right[i] = 1 + right[(i + 1) % n];
      }
    }
  }
  int res = 1e18;
  FOR (shift, -2 * n, 2 * n) {
    VPII ps;
    int cand = abs(shift);
    REP (i, n) {
      int dest = (i + shift + 3 * n) % n;
      int abs_s = abs(shift);
      if (s1[i] != s2[dest]) {
        cand++;
        int l = i;
        int r = dest;
        if (shift < 0) {
          swap(l, r);
        }
        int is1in = left[r] <= abs_s;
        if (!is1in) {
          ps.PB({left[l], right[r]});
        }
      }
    }
    if (ps.empty()) {
      mini(res, cand);
    } else {
      sort(ALL(ps));
      VPII st;
      for (auto p : ps) {
        while (!st.empty() && st.back().nd <= p.nd) {
          st.pop_back();
        }
        st.PB(p);
      }
      int bon = 2 * min(st[0].nd, st.back().st);
      REP (i, SZ(st) - 1) {
        mini(bon, 2 * (st[i].st + st[i + 1].nd));
      }
      mini(res, cand + bon);
    }
  }
  cout<<res<<endl;
      
    
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  return 0;
}


Measured memory_bytes: 384