//header
#ifdef LOCAL
    #include "cxx-prettyprint-master/prettyprint.hpp"
    #define print(x) cout << x << endl
#else
    #define print(...) 42
#endif
    #pragma GCC optimize("Ofast")
    #include <bits/stdc++.h>
    //types
    using namespace std;
    using ll = long long;
    typedef pair < ll , ll >P;
    typedef vector<ll> vl;
    template< typename T >
    using mat = vector< vector< T > >;
    template <std::uint_fast64_t Modulus> class modint {
        using u64 = std::uint_fast64_t;

        public:
        u64 a;

        constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {}
        constexpr u64 &value() noexcept { return a; }
        constexpr const u64 &value() const noexcept { return a; }
        constexpr modint operator+(const modint rhs) const noexcept {
            return modint(*this) += rhs;
        }
        constexpr modint operator-(const modint rhs) const noexcept {
            return modint(*this) -= rhs;
        }
        constexpr modint operator*(const modint rhs) const noexcept {
            return modint(*this) *= rhs;
        }
        constexpr modint operator/(const modint rhs) const noexcept {
            return modint(*this) /= rhs;
        }
        constexpr modint &operator+=(const modint rhs) noexcept {
            a += rhs.a;
            if (a >= Modulus) {
            a -= Modulus;
            }
            return *this;
        }
        constexpr modint &operator-=(const modint rhs) noexcept {
            if (a < rhs.a) {
            a += Modulus;
            }
            a -= rhs.a;
            return *this;
        }
        constexpr modint &operator*=(const modint rhs) noexcept {
            a = a * rhs.a % Modulus;
            return *this;
        }
        constexpr modint &operator/=(modint rhs) noexcept {
            u64 exp = Modulus - 2;
            while (exp) {
            if (exp % 2) {
                *this *= rhs;
            }
            rhs *= rhs;
            exp /= 2;
            }
            return *this;
        }
        };
    //abbreviations
    #define all(x) (x).begin(), (x).end()
    #define reverse(x) (x).rbegin(), (x).rend()
    #define rep2(i,a,b) for(ll i=(a);i<(b);++i)
    #define rep(i,n) for(ll i=0;i<(n);++i)
    #define SZ(x) ((ll)(x).size())
    #define sum(x) accumulate(begin(x), end(x), 0LL)//?
    #define pb(x) push_back(x)
    //functions
    ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
    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 (b<a) { a=b; return 1; } return 0; }
    template< typename T >
    T mod_pow(T x, T n, const T &p) {
        T ret = 1;
        while(n > 0) {
            if(n & 1) (ret *= x) %= p;
            (x *= x) %= p;
            n >>= 1;
        }
        return ret;
    }
    uint64_t my_rand(void) {
        static uint64_t x = 88172645463325252ULL;
        x = x ^ (x << 13); x = x ^ (x >> 7);
        return x = x ^ (x << 17);
    }

//constant
#define INF 1'010'000'000'000'000'017LL
#define mod 1'000'000'007LL
#define eps 0.0001
//library
void warshall_floyd(vector<vector<ll>> &g){
        for(int k = 0; k < g.size(); k++) {
                for(int i = 0; i < g.size(); i++) {
                        for(int j = 0; j < g.size(); j++) {
                                if(g[i][k] == INF || g[k][j] == INF) continue;
                                g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
                        }
                }
        }
}
//main
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout<<fixed<<setprecision(20);
    ll n;cin>>n;
    mat<ll>X(2, vl(n));
    rep(i, n)cin>>X[0][i];
    rep(i, n)cin>>X[1][i];
    mat<ll> dp(1<<n, vl(n, INF));
    rep(i, n)dp[0][i] = 0;
    rep2(s, 1, 1<<n){
        ll l = 0;
        rep(i, n){
            if((1<<i)&s)l++;
        }
        ll cnt = 0;
        rep(i, n){
            if(((1<<i)&s) == 0)continue;
            if(l == 1){
                dp[s][i] = 0;
                continue;
            }
            cnt++;
            ll a =X[abs(i-l+1)%2][i];
            rep(j, n){
                if(((1<<j)&s) == 0 or i == j)continue;
                ll b = X[abs(j-l)%2][j];
                if(a<b)continue;
                chmin(dp[s][i], dp[s^(1<<i)][j]+l-cnt);
            }
        }
    }
    ll ans = *min_element(all(dp[(1<<n)-1]));
    if(ans == INF)ans = -1;
    cout<<ans<<endl;
}

Measured memory_bytes: 49408