/**
*    author:  ekusiadadus
*    created: 11.04.2021 03:33:32
**/

#include<bits/stdc++.h>
using namespace std;
using i64 = long long;

int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  #ifndef ONLINE_JUDGE
  freopen("input.txt","r",stdin);
  freopen("output.txt","w",stdout);
  #endif
  int n;
  cin >> n;
  vector<int> v(2*n);
  for(int i = 0; i < 2*n; ++i){
    cin >> v[i]; 
  }
  multiset<int> s;
  int l = 0;
  int r = 2*n -1;
  i64  ans = 0;
  while(l<r){
    s.insert(v[l]);
    s.insert(v[r]);
    auto it = prev(s.end());
    ans += *it;
    s.erase(it);
    l += 1;
    r -= 1;
  }
  cout << ans << endl;
  return 0;
}
#include <bits/stdc++.h>
// #include <atcoder/all>
// using namespace atcoder;
#define rep(i, n) for (ll i = 0; i < (ll)(n); ++i)
#define rep2(i, s, n) for (ll i = s; i < (ll)(n); i++)
#define repr(i, n) for (ll i = n; i >= 0; i--)
#define pb push_back
#define COUT(x) cout << (x) << "\n"
#define COUTF(x) cout << setprecision(15) << (x) << "\n"
#define ENDL cout << "\n"
#define DF(x) x.erase(x.begin())
#define ALL(x) x.begin(), x.end()
#define SORT(x) sort(ALL(x))
#define RSORT(x) sort(x.rbegin(), x.rend())
#define REVERSE(x) reverse(ALL(x))
#define MAX(x) *max_element(ALL(x))
#define MAXI(x) max_element(ALL(x)) - x.begin()
#define SUM(x) accumulate(ALL(x), 0ll)
#define COUNT(x, y) count(ALL(x), y);
#define ANS cout << ans << "\n"
#define YES cout << "YES\n";
#define NO cout << "NO\n";
#define Yes cout << "Yes\n";
#define No cout << "No\n";
#define init() \
  cin.tie(0);  \
  ios::sync_with_stdio(false)
#define debug(x) cerr << "[debug] " << #x << ": " << x << endl;
#define debugV(v)                       \
  cerr << "[debugV] " << #v << ":";     \
  rep(z, v.size()) cerr << " " << v[z]; \
  cerr << endl;
using namespace std;
using ll = long long;
using ld = long double;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
using mll = map<ll, ll>;
using qll = queue<ll>;
using P = pair<ll, ll>;
using vp = vector<P>;
using vs = vector<string>;

template <typename T>
inline istream& operator>>(istream& i, vector<T>& v) {
  rep(j, v.size()) i >> v[j];
  return i;
}

template <typename T1, typename T2>
inline istream& operator>>(istream& i, pair<T1, T2>& v) {
  return i >> v.first >> v.second;
}

constexpr ll INF = 0x3f3f3f3f3f3f3f3f;
constexpr ld PI = 3.141592653589793238462643383279;
ll get_digit(ll x) {
  return to_string(x).size();
}

ll gcd(ll x, ll y) {
  return y ? gcd(y, x % y) : x;
}

ll lcm(ll a, ll b) {
  return a / gcd(a, b) * b;
}

template <class T>
void chmax(T& a, const T& b) {
  if (a < b) a = b;
}

template <class T>
void chmin(T& a, const T& b) {
  if (b < a) a = b;
}

signed main() {
  init();
  ll N;
  cin >> N;
  vll V(2 * N);
  cin >> V;
  priority_queue<ll, vll, greater<ll>> q;
  ll ans = 0;
  rep(i, N) {
    q.push(V[N - 1 - i]);
    q.push(V[N + i]);
    ans += q.top();
    q.pop();
  }
  ans = SUM(V) - ans;
  ANS;

  return 0;
}