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

template<class T>
bool chmax(T& a, const T& b) {
    if (a < b) { a = b; return true; }
    return false;
}
template<class T>
bool chmin(T& a, const T& b) {
    if (b < a) { a = b; return true; }
    return false;
}

// std::vector Declaration
template<typename T>
vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T, typename... Ts>
auto make_v(size_t a, Ts... ts) {
    return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

// std::vector Declaration and Initialization
template<typename T>
vector<T> make_vector(size_t a, T x) { return vector<T>(a, x); }
template<typename T, typename U, typename... Ts>
auto make_vector(size_t a, U b, Ts... ts) {
    return vector<decltype(make_vector<T>(b,ts...))>(a, make_vector<T>(b, ts...));
}

// std::vector Input
template<typename T>
istream& operator>>(istream& is, vector<T>& v) {
    for (auto &e : v) is >> e;
    return is;
}

// std::vector Debug
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    os << "[";
    bool a = 1;
    for (auto e : v) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::array Debug
template<typename T, size_t n>
ostream& operator<<(ostream& os, const array<T, n>& v) {
    os << "[";
    bool a = 1;
    for (auto e : v) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::deque Debug
template<typename T>
ostream& operator<<(ostream& os, const deque<T>& d) {
    os << "[";
    bool a = 1;
    for (auto e : d) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::pair Debug
template<typename T, typename U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    os << "(" << p.first << " " << p.second << ")";
    return os;
}

// std::set Debug
template<typename T>
ostream& operator<<(ostream& os, const set<T>& st) {
    os << "{";
    bool a = 1;
    for (auto e : st) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "}";
    return os;
}

// std::multiset Debug
template<typename T>
ostream& operator<<(ostream& os, const multiset<T>& st) {
    os << "{";
    bool a = 1;
    for (auto e : st) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "}";
    return os;
}

// std::map Debug
template<typename T, typename U>
ostream& operator<<(ostream& os, const map<T, U>& mp) {
    os << "{";
    bool a = 1;
    for (auto e : mp) {
        os << (a ? "" : " ");
        os << e.first << ":" << e.second;
        a = 0;
    }
    os << "}";
    return os;
}

// std::tuple Debug
template<int N, class Tuple>
void out(ostream& os, const Tuple& t){}
template<int N, class Tuple, class H, class ...Ts>
void out(ostream& os, const Tuple& t) {
    if (N) os << " ";
    os << get<N>(t);
    out<N+1,Tuple,Ts...>(os, t);
}
template<class ...Ts>
ostream& operator<<(ostream& os, const tuple<Ts...>& t) {
    os << "(";
    out<0,tuple<Ts...>,Ts...>(os, t);
    os << ")";
    return os;
}

// Debug
#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl

// Weighted edge
template<typename T>
struct edge {
    int src, to;
    T cost;

    edge(int to, T cost) : src(-1), to(to), cost(cost) {}
    edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

    friend ostream& operator<<(ostream& os, const edge& e) {
        return os << "(" << e.src << "->" << e.to << ":" << e.cost << ")";
    }
};

using LL = long long;

#define fs first
#define sc second

const LL MOD = 1e9+7;


template<typename T>
struct BIT {
    vector<T> bit;
    int sz;

    BIT(int n) : sz(n+1), bit(n+1) {}

    void add(int i, T x) {
        i += 1;
        while (i < sz) { bit[i] += x; i += i & -i; }
    }

    T sum(int i) {
        i += 1; T s = 0;
        while (i > 0) { s += bit[i]; i -= i & -i; }
        return s;
    }
};

template<typename T>
LL inversion(const vector<T>& A)
{
    map<T, int> idx;
    for (const T& a : A) idx[a] = -1;

    int cnt = 0;
    for (auto& p : idx) p.second = cnt++;

    assert(cnt == A.size());

    BIT<int> bit(cnt+1);
    LL res = 0;
    for (int i = 0; i < A.size(); ++i) {
        res += i - bit.sum(idx[A[i]]);
        bit.add(idx[A[i]], 1);
    }

    return res;
}


int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);

    int n; cin >> n;
    vector<int> a(n), b(n);
    cin >> a; cin >> b;

    int odd = 0, even = 0;
    for (int i = 0; i < n; ++i) {
        (i & 1 ? odd : even) |= 1<<i;
    }

    LL ans = numeric_limits<LL>::max();
    for (int s = 0; s < 1<<n; ++s) {
        if (__builtin_popcount(odd & s | even & ~s) != (n+1)/2 ||
            __builtin_popcount(even & s | odd & ~s) != n/2) {
            continue;
        }
        map<int,set<int>> black, white;
        for (int i = 0; i < n; ++i) {
            if (i & 1) {
                if (s & 1<<i) {
                    black[b[i]].insert(i);
                } else {
                    white[a[i]].insert(i);
                }
            } else {
                if (s & 1<<i) {
                    white[b[i]].insert(i);
                } else {
                    black[a[i]].insert(i);
                }
            }
        }

        vector<int> sb, sw;
        for (auto tp : black) {
            for (int k = 0; k < tp.sc.size(); ++k) {
                sb.emplace_back(tp.fs);
            }
        }
        for (auto tp : white) {
            for (int k = 0; k < tp.sc.size(); ++k) {
                sw.emplace_back(tp.fs);
            }
        }
        sort(sb.begin(), sb.end());
        sort(sw.begin(), sw.end());

        vector<int> ss(n);
        for (int i = 0; i < n; ++i) {
            ss[i] = (i & 1 ? sw[i/2] : sb[i/2]);
        }

        bool valid = true;
        for (int i = 0; i < n-1; ++i) {
            if (ss[i] > ss[i+1]) {
                valid = false;
                break;
            }
        }
        if (!valid) {
            continue;
        }


        vector<int> idx(n);
        {
            int cnt = 0;
            for (auto tp : black) {
                for (auto e : tp.sc) {
                    idx[e] = cnt;
                    cnt += 2;
                }
            }
        }
        {
            int cnt = 1;
            for (auto tp : white) {
                for (auto e : tp.sc) {
                    idx[e] = cnt;
                    cnt += 2;
                }
            }
        }

        chmin(ans, inversion(idx));
    }

    cout << (ans == numeric_limits<LL>::max() ? -1 : ans) << endl;

    return 0;
}


Measured memory_bytes: 256