#include<algorithm>
#include<bitset>
#include<cassert>
#include<cfloat>
#include<climits>
#include<cmath>
#include<deque>
#include<functional>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<string>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

using lint = long long;
using P = pair<int, int>;
using LLP = pair<long long, long long>;

#define REP(i, x, n) for(int i = (x), i##_len = (int)(n) ; i < i##_len ; ++i)
#define rep(i, n) for(int i = 0, i##_len = (int)(n) ; i < i##_len ; ++i)
#define reps(i, n) for(int i = 1, i##_len = (int)(n) ; i <= i##_len ; ++i)
#define rrep(i, n) for(int i = (int)(n) - 1 ; i >= 0 ; --i)
#define rreps(i, n) for(int i = (int)(n) ; i > 0 ; --i)
#define SORT(x) sort((x).begin(), (x).end())
#define SORT_INV(x) sort((x).rbegin(), (x).rend())
#define REVERSE(x) reverse((x).begin(), (x).end())
#define TWINS(x) cout << ((x) ? "Yay!" : ":(") << '\n'
#define endl '\n'

constexpr int IINF = (1 << 30) - 1;
constexpr long long LLINF = 1LL << 61;
constexpr double EPS = 1e-10;

constexpr int dx4[] = {1, 0, -1, 0}, dy4[] = {0, 1, 0, -1};
constexpr int dx8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dy8[] = {0, -1, -1, -1, 0, 1, 1, 1};

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

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

int dp[18][1 << 18];

int solve(void){
    int n;
    cin >> n;

    vector<int> a(n);
    rep(i, n){
        cin >> a[i];
        --a[i];
    }

    vector<int> b(n);
    rep(i, n){
        cin >> b[i];
        --b[i];
    }

    vector<int> v1(n), v2(n);
    rep(i, n){
        if(i & 1){
            v1[i] = a[i];
            v2[i] = b[i];
        }else{
            v1[i] = b[i];
            v2[i] = a[i];
        }
    }

    fill(dp[0], dp[n], IINF);
    dp[0][0] = 0;
    rep(i, n){
        dp[i][1 << i] = i;
    }

    vector<int> v;
    REP(i, 1, 1 << n){
        v.emplace_back(i);
    }

    auto comp = [&](int i, int j){
        int cnti = 0;
        int cntj = 0;
        rep(k, n){
            cnti += (i >> k & 1);
            cntj += (j >> k & 1);
        }
        return cnti < cntj;
    };

    sort(v.begin(), v.end(), comp);

    for(auto bit : v){
        vector<int> sumi, mada;
        int cnt = 0;
        rep(i, n){
            if(bit >> i & 1){
                sumi.emplace_back(i);
                ++cnt;
            }else{
                mada.emplace_back(i);
            }
        }

        for(auto mae : sumi){
            for(auto tsugi : mada){
                if(cnt & 1){
                    if(v2[mae] > v1[tsugi]){
                        continue;
                    }
                }else{
                    if(v1[mae] > v2[tsugi]){
                        continue;
                    }
                }
                int cost = IINF;
                if(tsugi < cnt){
                    cost = abs((cnt-tsugi)-(sumi.end()-upper_bound(sumi.begin(), sumi.end(), tsugi)));
                }else{
                    cost = (tsugi-cnt)+(sumi.end()-upper_bound(sumi.begin(), sumi.end(), tsugi));
                }
                chmin(dp[tsugi][bit | (1 << tsugi)], dp[mae][bit]+cost);
            }
        }
    }

    int res = IINF;
    rep(i, n){
        chmin(res, dp[i][(1 << n)-1]);
    }

    if(res < IINF){
        return res;
    }

    return -1;
}

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

    int ans = solve();
    cout << ans << endl;

    cout << flush;

    return 0;
}

Measured memory_bytes: 19960