#define DEBUG 0
#include <bits/stdc++.h>
#define loop(n) for (lint ngtkana_is_a_genius = 0; ngtkana_is_a_genius < lint(n); ngtkana_is_a_genius++)
#define rep(i, begin, end) for (lint i = lint(begin); (i) < lint(end); i++)
#define all(v) v.begin(), v.end()
#define rand(l, r) std::uniform_int_distribution<>(l, r)(mt)
using lint = long long;
auto mt = std::mt19937_64(std::random_device{}());
auto cmn = [](auto&& a, auto b){ if (a > b) {a = b; return true;} return false; };
auto cmx = [](auto&& a, auto b){ if (a < b) {a = b; return true;} return false; };
void debug_impl() { std::cerr << std::endl; }
template <typename Head, typename... Tail>
void debug_impl(Head head, Tail... tail) { std::cerr << " " << head; debug_impl(tail...); }
#if DEBUG
#define debug(...)\
  do {\
    std::cerr << std::boolalpha << "[" << #__VA_ARGS__ << "]:";\
    debug_impl(__VA_ARGS__);\
    std::cerr << std::noboolalpha;\
  } while (false)
#else
#define debug(...) {}
#endif

template < typename Container, typename Value = typename Container::value_type, std::enable_if_t<!std::is_same< Container, std::string >::value, std::nullptr_t> = nullptr>
std::istream& operator>> (std::istream& is, Container& v)
  { for (auto & x : v) { is >> x; } return is; }

template < typename Container, typename Value = typename Container::value_type, std::enable_if_t<!std::is_same< Container, std::string >::value, std::nullptr_t> = nullptr >
std::ostream& operator<< (std::ostream& os, Container const& v) {
 os << "{";
  for (auto it = v.begin(); it != v.end(); it++)
    {os << (it != v.begin() ? "," : "") << *it;}
  return os << "}";
}

template < template < typename ... > class Tuple,  typename... Args, std::size_t ... Inds, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::istream& tuple_input_impl(std::istream& os, Tuple<Args...>& tuple, std::integer_sequence<std::size_t, Inds...>)
  { (void)std::initializer_list<int>{((void)(os >> std::get< Inds >(tuple)), 0)...}; return os; }
template < template < typename ... > class Tuple,  typename... Args, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::istream& operator>> (std::istream& os, Tuple<Args...>& tuple)
  { return tuple_input_impl(os, tuple, std::index_sequence_for<Args...>()); }

template < template < typename ... > class Tuple,  typename... Args, std::size_t ... Inds, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::ostream& tuple_output_impl(std::ostream& os, const Tuple<Args...>& tuple, std::integer_sequence<std::size_t, Inds...>)
  { os << "("; (void)std::initializer_list<int>{((void)(os << (Inds > 0 ? "," : "") << std::get< Inds >(tuple)), 0)...}; return os << ")"; }
template < template < typename ... > class Tuple,  typename... Args, std::size_t = std::tuple_size< Tuple < Args ... > >::value >
std::ostream& operator<< (std::ostream& os, const Tuple<Args...>& tuple)
 { return tuple_output_impl(os, tuple, std::index_sequence_for<Args...>()); }

template < class Value >
bool bat(Value x, std::size_t pos) { return (x >> pos) & Value{1}; }

int main() {
  std::cin.tie(0); std::cin.sync_with_stdio(false);
  int n; std::cin >> n;
  int N = 1 << n;
  std::vector<int> a(n), b(n); std::cin>>a>>b;
  debug(a,b);

  int inf = std::numeric_limits<int>::max();
  auto cal = [&] (int bs) {
    std::vector<std::vector<std::pair<int,int>>> data(2);
    rep(i,0,n) {
      int parity = (i % 2) ^ bat(bs, i);
      int value = (bat(bs, i) ? b : a).at(i);
      data.at(parity).emplace_back(value, i);
    }
    if ((int)data.at(1).size() != n / 2) return inf;
    for (auto&& v : data) {
      std::sort(all(v));
    }
    debug(data);

    std::vector<std::pair<int,int>> p(n);
    rep(i,0,n) {
      int parity = i % 2;
      int j = i / 2;
      p.at(i) = data.at(parity).at(j);
    }
    debug(p);

    rep(i,0,n-1) {
      if (p.at(i).first > p.at(i+1).first) return inf;
    }

    int ans = 0;
    std::vector<int> ckd(n);
    for (auto pair : p) {
      int x = pair.second;
      rep(i,x,n) ans += ckd.at(i);
      ckd.at(x) = true;
    }
    debug(ckd);
    return ans;
  };

  int ans = inf;
  rep(bs, 0, N) {
    if (__builtin_popcount(bs) % 2 == 1) continue;
    cmn(ans, cal(bs));
  }
  if (ans == inf) ans = -1;
  std::cout << ans << std::endl;
  return 0;
}

Measured memory_bytes: 384