// clang-format off
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define stoi stoll
using pii = pair<int,int>;
using vi = vector<int>;
using vvi = vector<vi>;
#define all(c) begin(c), end(c)
#define rall(c) rbegin(c), rend(c)
#define fore(x, c) for(auto &&x : c)
#define rep(i, a, n) for(int i = a, i##len = (int)(n); i < i##len; ++i)
#define rrep(i, a, n) for(int i = (int)(n - 1); i >= a; --i)
#define sz(c) ((int)c.size())
#define contains(c, x) (c.find(x) != end(c))
#define inseg(l, x, r) ((l) <= (x) && (x) < (r))
#define dump(...)
#define pb push_back
#define eb emplace_back
#define _ 0
const signed INF_ = 1001001001; const long long INF = 1001001001001001001LL;
const int DX[9] = {0,1,0,-1,1,1,-1,-1,0}, DY[9] = {-1,0,1,0,-1,1,1,-1,0};
template<class T> ostream& operator<<(ostream &os, const vector<T> &v) {
  for (auto i = begin(v); i != end(v); i++) os<<*i<<(i==end(v)-1?"":" ");return os;}
template<class T> istream& operator>>(istream &is, vector<T> &v) {
  for (auto i = begin(v); i != end(v); i++) is>>*i;return is;}
template<class T,class U> istream& operator>>(istream &is, pair<T,U> &p) {
  is>>p.first>>p.second;return is;}
template<class T, class U> bool chmax(T &a, const U &b){return a<b?a=b,1:0;}
template<class T, class U> bool chmin(T &a, const U &b){return a>b?a=b,1:0;}
template <class T> void psum(T& c) {partial_sum(begin(c), end(c), begin(c));}
template<class T> using heap = priority_queue<T, deque<T>, greater<T>>;
struct before_main_function {
  before_main_function() {
      cin.tie(nullptr); ios::sync_with_stdio(0);
      cout << setprecision(15) << fixed;
  }
} before_main_function;
// clang-format on
//------------------8<------------------------------------8<--------------------

// 1-indexed
struct BIT {
  int size;
  int pow2_less;
  vector<int> data;
  BIT(int n) : size(n + 1), data(n + 1, 0) {
    pow2_less = 1;
    while ((pow2_less << 1) <= size) pow2_less <<= 1;
  }
  void add(int i, int x) {
    while (i < size) {
      data[i] += x;
      i += i & -i;
    }
  }
  int sum(int i) {
    int ret = 0;
    while (i > 0) {
      ret += data[i];
      i -= i & -i;
    }
    return ret;
  }
  // sum(x) >= w となる最小のxを返す
  int lower_bound(int w) {
    if (w <= 0) return 0;
    int x = 0;
    for (int k = pow2_less; k > 0; k >>= 1) {
      if (x + k < size && data[x + k] < w) {
        w -= data[x + k];
        x += k;
      }
    }
    return x + 1;
  }
};
signed main() {
  int N;
  cin >> N;
  vector<int> A(N), B(N);
  cin >> A >> B;

  int ans = INF;
  rep(S, 0, 1 << N) {
    vector<vector<tuple<int, int, int>>> even_odd(2);
    rep(i, 0, N) {
      if (S >> i & 1)
        even_odd[i % 2].emplace_back(A[i], i, 0);
      else
        even_odd[(i % 2) ^ 1].emplace_back(B[i], i, 1);
    }
    if (sz(even_odd[0]) != N / 2 + N % 2) continue;
    if (sz(even_odd[1]) != N / 2) continue;

    sort(all(even_odd[0]));
    sort(all(even_odd[1]));
    vector<tuple<int, int, int>> t(N);
    rrep(i, 0, N) {
      t[i] = even_odd[i % 2].back();
      even_odd[i % 2].pop_back();
    }
    bool valid = true;
    rep(i, 0, N - 1) {
      if (get<0>(t[i]) > get<0>(t[i + 1])) valid = false;
    }
    if (!valid) continue;

    dump(S);
    int tmp = 0;
    BIT bit(N + 1);
    rep(i, 0, N) {
      int v, idx, ab;
      tie(v, idx, ab) = t[i];
      dump(v, idx, ab);
      tmp += bit.sum(N) - bit.sum(idx + 1);
      bit.add(idx + 1, 1);
    }
    chmin(ans, tmp);
  }

  if (ans == INF) ans = -1;
  cout << ans << endl;
  return (0 ^ _ ^ 0);
}



Measured memory_bytes: 256