// #define DEBUGGING
#include <bits/stdc++.h>
#define endl '\n'
#define ALL(V) (V).begin(), (V).end()
#define ALLR(V) (V).rbegin(), (V).rend()
template <typename T> using V = std::vector<T>;
template <typename T> using VV = V<V<T>>;
using ll = std::int64_t;
using ull = std::uint64_t;
using PLL = std::pair<ll, ll>;
using TLL = std::tuple<ll, ll, ll>;
template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return std::min(t, var_min(tail...)); }
template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return std::max(t, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
template <typename T> const T& clamp(const T &t, const T &low, const T &high) { return std::max(low, std::min(high, t)); }
template <typename T> void chclamp(T &t, const T &low, const T &high) { return t = clamp(t, low, high); }
namespace init__ { struct InitIO { InitIO() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(30); } } init_io; }
#define mv_rec make_v(init, tail...)
template <typename T> T make_v(T init) { return init; }
template <typename T, typename... Tail> auto make_v(T init, size_t s, Tail... tail) { return V<decltype(mv_rec)>(s, mv_rec); }
#undef mv_rec
using namespace std;
#ifdef DEBUGGING
#include "../../debug/debug.cpp"
#else
#define DEBUG(...) 0
#define DEBUG_SEPARATOR_LINE 0
#endif

const ll inf = 5e15;

ll solve(const string &A, const string &B) {
    ll N = A.size();
    string B3 = B + B + B;
    V<ll> left(N), right(N);
    while(B3[N - left[0]] == '0') left[0]++;
    while(B3[2 * N - 1 + right[N - 1]] == '0') right[N - 1]++;
    for(ll i = 1; i < N; i++) {
        left[i] = (B[i] == '1' ? 0 : left[i - 1] + 1);
    }
    for(ll i = N - 2; 0 <= i; i--) {
        right[i] = (B[i] == '1' ? 0 : right[i + 1] + 1);
    }

    DEBUG(left, right);

    ll ans = inf;
    V<PLL> lis(N + 10);
    for(ll i = 0; i <= N; i++) {
        ll idx = 0;
        ll cnt = 0;
        for(ll j = 0; j < N; j++) {
            char a = A[j], b = B3[N - i + j];
            if(a == b) continue;
            cnt++;
            if(i < left[j]) lis[idx++] = PLL(right[j], left[j]);
        }
        lis[idx++] = PLL(0, -1);
        sort(lis.begin(), lis.begin() + idx);
        multiset<ll, greater<ll>> st;
        for(ll j = 0; j < idx; j++) st.insert(lis[j].second);
        for(ll j = 0; j < idx; j++) {
            ll tmp = cnt + 2 * max<ll>(0, lis[j].first) + i;
            auto ite = st.find(lis[j].second);
            st.erase(ite);
            if(st.size()) {
                ll val = *st.begin();
                tmp += 2 * (val - i);
            }
            chmin(ans, tmp);
            DEBUG(make_tuple(i, ans, cnt, tmp, lis[j].first, *st.begin()));
        }
    }
    return ans;
}

ll solve() {
    string A, B;
    cin >> A >> B;

    {
        string zero = string(B.size(), '0');
        if(B == zero) return A == B ? 0 : -1;
    }

    ll ans = inf;
    chmin(ans, solve(A, B));
    reverse(ALL(A));
    reverse(ALL(B));
    chmin(ans, solve(A, B));
    return ans;
}

int main() {
    cout << solve() << endl;
    return 0;
}


Measured memory_bytes: 476