#include <bits/stdc++.h>
 
//#include <unistd.h>
//#include <iostream>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
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 (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
//const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

int n;
vi a, b;

signed main() {
  fio();
  cin >> n;
  a.resize(n); b.resize(n);
  rep (i, n) {
    cin >> a[i];
  }
  rep (i, n) {
    cin >> b[i];
  }

  vi perm;
  for (int i = 0; i < n; i += 2) {
    perm.push_back(0);
  }
  for (int i = 1; i < n; i += 2) {
    perm.push_back(1);
  }

  int ans = inf;
  int cnt = 0;
  do {
    vi odd, even;
    rep (i, n) {
      if (perm[i]) {
        if (i % 2 == 1) {
          odd.push_back(a[i]);
        }
        else {
          odd.push_back(b[i]);
        }
      }
      else {
        if (i % 2 == 0) {
          even.push_back(a[i]);
        }
        else {
          even.push_back(b[i]);
        }
      }
    }

    vi odd2 = odd;
    vi even2 = even;
    sort(all(odd2));
    sort(all(even2));
    vi c(n);
    rep (i, n) {
      if (i % 2 == 0) {
        c[i] = even2[i / 2];
      }
      else {
        c[i] = odd2[i / 2];
      }
    }
    /*
    DEBUG_VEC(odd);
    DEBUG_VEC(even);
    DEBUG_VEC(perm);
    DEBUG_VEC(c);
    //*/

    bool flag = true;
    for (int i = 1; i < n; i++) {
      if (c[i] < c[i - 1]) {
        flag = false;
        break;
      }
    }
    if (not flag) continue;

    vector<bool> used(n);
    int res = 0;
    rep (i, n) {
      int add = 0;
      for (int j = 0; j < n; j++) {
        if (used[j]) continue;
        if (perm[j] != i % 2) {
          add++;
          continue;
        }
        int x;
        if (i % 2 == j % 2) {
          x = a[j];
        }
        else {
          x = b[j];
        }
        if (x == c[i]) {
          used[j] = true;
          res += add;
          break;
        }
        add++;
      }
    }
    chmin(ans, res);
  } while (next_permutation(all(perm)));
  if (ans == inf) {
    cout << -1 << endl;
  }
  else {
    cout << ans << endl;
  }
}

Measured memory_bytes: 256