#pragma target("avx")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef unordered_map<ll, ll> U_MAP;
typedef priority_queue<ll> pq;
typedef priority_queue<ll, vector<ll>, greater<ll>> rpq;
const int INF = 1e9, MOD = 1e9 + 7, ohara = 1e6 + 10;
const ll LINF = 1e18;

#define rep(i, n) for (ll(i) = 0; (i) < (int)(n); (i)++)
#define rrep(i, a, b) for (ll i = (a); i < (b); i++)
#define rrrep(i, a, b) for (ll i = (a); i >= (b); i--)
#define all(v) (v).begin(), (v).end()
#define Size(n) (n).size()
#define Cout(x) cout << (x) << endl
#define doublecout(a) cout << fixed << setprecision(15) << a << endl;
#define fi first
#define se second
#define m_p make_pair
#define p_b push_back
string to_string(string s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

//------ Believe yourself as a genius!!!!!! ------

int dy[] = {1, 0, -1, 0};
int dx[] = {0, 1, 0, -1};
// int dy[]={-1,0,1,-1,1,-1,0,1};int dx[]={-1,-1,-1,0,0,1,1,1};
string alph("abcdefghijklmnopqrstuvwxyz"), s;
ll n, cnt, ans, a[100], b[100], c, d, tmp, m, h, w, x, y, sum, k, q;

int main(void) {
  cin.tie(0);
  cout.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;
  rep(i, n) cin >> a[i];
  rep(i, n) cin >> b[i];

  ans = LINF;
  for (int bit = 0; bit < (1 << (n)); bit++) {
    ll ura[n + 10] = {}, odd = 0, even = 0;
    ll ev_now, od_now;
    P p_odd[n + 10], p_even[n + 10], p[n + 10];
    rep(i, n) {
      if (bit & (1 << i)) {
        ura[i] = 1;
      }
    }
    // 1が裏
    rep(i, n) {
      if (i % 2 == 0) {
        if (ura[i] == 1)
          p_odd[odd] = m_p(b[i], i), odd++;
        else
          p_even[even] = m_p(a[i], i), even++;
      } else {
        if (ura[i] == 1)
          p_even[even] = m_p(b[i], i), even++;
        else
          p_odd[odd] = m_p(a[i], i), odd++;
      }
    }
    if (odd != n / 2) continue;
    if (even != (n + 1) / 2) continue;
    sort(p_even, p_even + even);
    sort(p_odd, p_odd + odd);
    ev_now = 0, od_now = 0;
    rep(i, n) {
      if (i % 2 == 0) {
        p[i] = p_even[ev_now++];
      } else {
        p[i] = p_odd[od_now++];
      }
    }
    int ok = 0;
    rep(i, n - 1) {
      if (p[i].fi <= p[i + 1].fi) continue;
      ok = 1;
    }
    if (ok) continue;
    cnt = 0;
    rrrep(i, n - 1, 0) {
      rep(j, i) {
        if (p[j].se > p[i].se) cnt++;
      }
    }
    ans = min(ans, cnt);
    debug(ans);
  }
  if (ans == LINF) ans = -1;
  Cout(ans);
  return 0;
}

Measured memory_bytes: 384