#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <math.h>
#include <iomanip>
#include <limits>
#include <list>
#include <queue>
#include <tuple>
#include <map>
#include <stack>
#include <set>
using namespace std;
#define fast_io ios_base::sync_with_stdio (false) ; cin.tie(0) ; cout.tie(0) ;
#define MOD (long long int)(1e9+7)
#define ll long long int
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define reps(i,n) for(int i=1; i<=(int)(n); i++)
#define REP(i,n) for(int i=n-1; i>=0; i--)
#define REPS(i,n) for(int i=n; i>0; i--)
#define INF (int)(1123456789)
#define LINF (long long int)(112345678901234567)
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
#define all(v) v.begin(), v.end()

typedef pair<int, int> Pii;
typedef pair<ll, ll> Pll;

ll mpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = mpow(a,b/2); return memo*memo%MOD;}
  else return mpow(a,b-1) * a % MOD;
}
ll lpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = lpow(a,b/2); return memo*memo;}
  else return lpow(a,b-1) * a;
}
ll gcd(ll a, ll b){
  if(b==0) return a;
  else return gcd(b, a%b);
}
vector<ll> kaijo_memo;
ll kaijo(ll n){
  if(kaijo_memo.size() > n) return kaijo_memo[n];
  if(kaijo_memo.size() == 0) kaijo_memo.push_back(1);
  while(kaijo_memo.size() <= n) kaijo_memo.push_back(kaijo_memo[kaijo_memo.size()-1] * kaijo_memo.size() % MOD);
  return kaijo_memo[n];
}
vector<ll> gyaku_kaijo_memo;
ll gyaku_kaijo(ll n){
  if(gyaku_kaijo_memo.size() > n) return gyaku_kaijo_memo[n];
  if(gyaku_kaijo_memo.size() == 0) gyaku_kaijo_memo.push_back(1);
  while(gyaku_kaijo_memo.size() <= n) gyaku_kaijo_memo.push_back(gyaku_kaijo_memo[gyaku_kaijo_memo.size()-1] * mpow(gyaku_kaijo_memo.size(), MOD-2) % MOD);
  return gyaku_kaijo_memo[n];
}

ll nCr(ll n, ll r){
  if(n == r) return 1;//0個の丸と-1個の棒みたいな時に時に効く？不安.
  if(n < r || r < 0) return 0;
  ll ret = 1;
  ret *= kaijo(n); ret %= MOD;
  ret *= gyaku_kaijo(r); ret %= MOD;
  ret *= gyaku_kaijo(n-r); ret %= MOD;
  return ret;
}

int main(void){
  fast_io
  int n;
  cin>>n;
  vector<ll> A,B;
  rep(i,n){
    ll a;cin>>a;
    A.push_back(a);
  }
  rep(i,n){
    ll b;cin>>b;
    B.push_back(b);
  }
  ll ans = LINF;
  vector<int> ans_ind;
  rep(bits, 1<<n){
    //cout<<bits<<endl;
    ll count = 0;
    rep(i,n){
      count += (1 - (bits>>i)&1);
    }
    if(count != (n+1)/2){
      continue;
    }

    vector<int> indexes;
    rep(i,n){
      indexes.push_back(i);
    }
    ll hoge_ans = 0;
    bool ok = true;
    ll memo = -1;
    rep(i,n){
      int min_j = -1;
      int min_val = INF;
      /*rep(j,4){
        cout<<indexes[j]<<" ";
      }
      cout<<endl;*/
      rep(j,n){
        if(j < i) continue;
        int index = indexes[j];
        if(((bits>>index) & 1) != i % 2) continue;
        int val = (index % 2 == i % 2) ? A[index] : B[index];
        if(val < min_val){
          min_val = val;
          min_j = j;
        }
      }
      //cout<<min_j<<" "<<min_val<<endl;
      if(memo > min_val){
        ok = false;
        break;
      }
      memo = min_val;
      for(int j=min_j-1; j>=i; j--){
        hoge_ans++;
        int tmp = indexes[j];
        indexes[j] = indexes[j+1];
        indexes[j+1] = tmp;
      }
    }
    if(!ok) continue;

    if(hoge_ans < ans){
      ans = hoge_ans;
      /*ans_ind.clear();
      rep(i,n){
        ans_ind.push_back(indexes[i]);
      }*/
    }
  }

  if(ans == LINF){
    cout<<-1<<endl;
    return 0;
  }

  /*rep(i,n){
    cout<<ans_ind[i]<<" ";
  }
  cout<<endl;*/
  /*int memo_v = -1;
  rep(i,ans_ind.size()){
    int ind = ans_ind[i];
    int val = -1;
    if(i%2 == ind%2){
      val = A[ind];
    }else{
      val = B[ind];
    }
    if(memo_v > val){
      while(true){

      }
    }
    memo_v = val;
  }*/

  cout<<ans<<endl;
  return 0;
}

Measured memory_bytes: 256