// includes
#include <bits/stdc++.h>
using namespace std;

// macros
#define pb emplace_back
#define mk make_pair
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define irep(itr, st) for(auto itr = (st).begin(); itr != (st).end(); ++itr)
#define irrep(itr, st) for(auto itr = (st).rbegin(); itr != (st).rend(); ++itr)
#define whole(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())
#define bit(n) (1LL<<(n))
// functions
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;}
template <typename T> istream &operator>>(istream &is, vector<T> &vec){for(auto &v: vec)is >> v; return is;}
template <typename T> ostream &operator<<(ostream &os, const vector<T>& vec){for(int i = 0; i < vec.size(); i++){ os << vec[i]; if(i + 1 != vec.size())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T>& st){for(auto itr = st.begin(); itr != st.end(); ++itr){ os << *itr; auto titr = itr; if(++titr != st.end())os << " ";} return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){os << p.first << " " << p.second; return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
template <typename T1, typename T2> ostream &operator<<(ostream &os, const unordered_map<T1, T2> &mp){for(auto itr = mp.begin(); itr != mp.end(); ++itr){ os << itr->first << ":" << itr->second; auto titr = itr; if(++titr != mp.end())os << " "; } return os;}
//  types
using ll = long long int;
using P = pair<int, int>;
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1000000007;
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
// io
struct fast_io{
  fast_io(){ios_base::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(20);}
} fast_io_;

ll tr(vector<int> v){
  ll res = 0;
  rep(i, sz(v)){
    FOR(j, i + 1, sz(v)){
      if(v[i] > v[j])++res;
    }
  }
  return res;
}

int main(int argc, char const* argv[])
{
  int n; cin >> n;
  vector<int> a(n), b(n); cin >> a >> b;
  ll res = linf;
  rep(i, bit(n)){
    vector<P> odd, even;
    rep(j, n){
      int c = ((i >> j) & 1) + (j & 1);
      vector<P> &C = ((c & 1) ? odd: even);
      if((i >> j) & 1)C.pb(b[j], j);
      else C.pb(a[j], j);
    }
    if(!(sz(even) == sz(odd) || sz(even) == sz(odd) + 1))continue;
    sort(whole(even));
    sort(whole(odd));
    vector<int> v;
    vector<int> vv;
    rep(j, sz(even)){
      v.pb(even[j].second);
      if(j < sz(odd))v.pb(odd[j].second);
      vv.pb(even[j].first);
      if(j < sz(odd))vv.pb(odd[j].first);
    }
    bool ok = true;
    rep(j, n - 1){
      if(vv[j] > vv[j+1]){
        ok = false;
        break;
      }
    }
    if(!ok)continue;
    // cerr << bitset<5>(i) << "|" << odd << "|" << even << "|" << v << "|" << tr(v) << endl;
    res = min(res, tr(v));
  }
  cout << (res == linf ? -1: res) << endl;
  return 0;
}


Measured memory_bytes: 256