// #define DEBUGGING
#include <bits/stdc++.h>
#define endl '\n'
#define ALL(V) (V).begin(), (V).end()
#define ALLR(V) (V).rbegin(), (V).rend()
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> using V = std::vector<T>;
template <typename T> using VV = V<V<T>>;
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;

// 0-indexed
// [l, r)
template <typename T>
struct Bit {
    V<T> data;
    T id_ele;

    Bit(ll size, T id_ele) : id_ele(id_ele) {
        ll bsize = 1;
        while(bsize < size) bsize *= 2;
        data = V<T>(bsize + 1, id_ele);
    }

    T sum(ll pos) {
        T ret = id_ele;
        for(; 0 < pos; pos -= pos & -pos) ret += data[pos];
        return ret;
    }

    T sum(ll l, ll r) { return sum(r) - sum(l); }

    void add(ll pos, T delta) {
        for(++pos; pos < data.size(); pos += pos & -pos) data[pos] += delta;
    }
};

int main() {
    ll N;
    cin >> N;
    V<ll> A(N), B(N);
    for (ll &e : A) cin >> e;
    for (ll &e : B) cin >> e;
    ll ans = inf;
    for (ll S = 0; S < (1ll << N); S++) {
        V<PLL> odds, evens;
        for (ll i = 0; i < N; i++) {
            bool p = ((S >> i) & 1 ? true : false);
            ll n = (p ? B[i] : A[i]);
            if (i % 2 == 0) (p ? odds : evens).emplace_back(n, i);
            else (p ? evens : odds).emplace_back(n, i);
        }

        sort(ALL(odds));
        sort(ALL(evens));
        ll pre = -1;
        Bit<ll> bt(N + 10, 0);
        ll cnt = 0;
        bool ok = true;
        for (ll i = 0; i < N; i++) {
            auto &&v = (i & 1 ? odds : evens);
            ll idx = i / 2;
            if (v.size() <= idx) {
                ok = false;
                break;
            }
            PLL ele = v[i / 2];
            ll a, b;
            tie(a, b) = ele;
            if (a < pre) {
                ok = false;
                break;
            }
            cnt += bt.sum(b, N + 10);
            bt.add(b, 1);
            pre = a;
        }

        DEBUG(make_tuple(cnt));
        if(ok) chmin(ans, cnt);
//        if (cnt == 0) DEBUG(arr, bitset<18>(S).to_string());
    }

    if (ans == inf) cout << -1;
    else cout << ans;
    cout << endl;
    return 0;
}


Measured memory_bytes: 384