#ifdef LOCAL
    #define _GLIBCXX_DEBUG
    #define __clock__
#else
    #pragma GCC optimize("Ofast")
#endif
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using VI = vector<ll>;
using VV = vector<VI>;
using VS = vector<string>;
using PII = pair<ll, ll>;

// tourist set
template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

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;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << '\n'; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
// tourist set 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 (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i,b) FOR(i, 0, b)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<'\n'
#define p2(s, t) cout << (s) << " " << (t) << '\n'
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << '\n'
#define p_yes() p("YES")
#define p_no() p("NO")
#define SZ(x) ((int)(x).size())
#define SORT(A) sort(ALL(A))
#define RSORT(A) sort(ALL(A), greater<ll>())
#define MP make_pair

void no(){p_no(); exit(0);}
void yes(){p_yes(); exit(0);}

const ll mod = 1e9 + 7;
const ll inf = 1e18;
const double PI = acos(-1);

bool isIncreasing(VI& V){
  VI A = V;
  SORT(A);
  ll N = V.size();
  rep(i, N){
    if(V[i]!=A[i]) return false;
  }
  return true;
}

// {val, index}のリストのvalのみ見てincreasing判定
bool isIncreasing2(vector<PII>& V){
  ll N = V.size();
  auto A = V;
  sort(ALL(A));
  rep(i, N){
    if(V[i].first!=A[i].first) return false;
  }
  return true;
}

// バブルソートして反転数を返す
ll bubble_sort(vector<ll> &A){
    ll N = A.size();    
    ll cnt=0;
    // iまで見る
    for(int i=N-1; i>=0; i--){
        FOR(j, 0, i){
            if(A[j] > A[j+1]){
                swap(A[j], A[j+1]);
                cnt++;
            }
        }
    }
    return cnt;
}

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

    // input
    ll N; 
    cin >> N;

    VI A(N);
    rep(i, N) cin>>A[i];

    VI B(N);
    rep(i, N) cin>>B[i];

    ll mi = inf;
    ll odd = N/2;
    ll even = N-odd;
    rep(f, 1LL<<N){
      vector<PII> OD; // odd vector // {val, index}のリスト
      vector<PII> EV; // even vector // 〃
      rep(i, N){
        if(f>>i&1){
          // 1だとひっくり返ってるとする
          if(i%2==0){
            OD.push_back(MP(B[i], i));
          }else{
            EV.push_back(MP(B[i], i));
          }
        }else{
          if(i%2==0){
            EV.push_back(MP(A[i], i));
          }else{
            OD.push_back(MP(A[i], i));
          }
        }
      }
      if(odd==SZ(OD) && even==SZ(EV)){
        // ok
      }else{
        // debug("skip by size");
        continue;
      }

      // odd, evenの数は合っている
      SORT(EV);
      SORT(OD);
      // zip (合成する)
      vector<PII> SO; // sorted vector
      rep(i, SZ(OD)){
        SO.push_back(EV[i]);
        SO.push_back(OD[i]);
      }
      if(SZ(EV)!=SZ(OD)){
        SO.push_back(EV.back());
      }

      // これがsortedかチェック
      if(isIncreasing2(SO)){
        // ok
      }else{
        // debug("skip by not sorted");
        continue;
      }

      // original vectorをsortedにするまでの回数が反転数
      VI I;
      for(auto pa : SO){
        I.push_back(pa.second);
      }
      
      ll h = bubble_sort(I);
      chmin(mi, h);
    }

    if(mi==inf){
      p(-1);
    }else{
      p(mi);
    }
    
    return 0;
}


Measured memory_bytes: 384