#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <vector>

#define REP(i,n)  for (int i = 0; i < (n); ++i)
#define SORT(a)   sort((a).begin(), (a).end());
#define UNIQ(a)   SORT(a);(a).erase(unique((a).begin(), (a).end()), (a).end());
#define FIND(a,x) find((a).begin(), (a).end(), (x)) != (a).end()

using namespace std;
using ll = long long;
using P = pair<int,int>;
using namespace std;

const int MOD = 1000000007; // 10^9 + 7

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

  int N; cin >> N;
  vector<ll> a(2 * N);
  REP(i, 2 * N) cin >> a[i];

  ll ans = 0;
  ll l = 0, r = 2 * N - 1;
  REP(i, N) {
    ll h1 = a[l], h2 = a[l + 1];

    ll len = r - l + 1;
    if (len == 2) {
      ans += abs(a[l] - a[r]);
    } else {
      ll t1 = a[r], t2 = a[r - 1];
      if (h1 - h2 > t1 - t2) {
        ans += h1 - h2;
        l += 2;
      } else {
        ans += t1 - t2;
        r -= 2;
      }
    }
  }
  cout << ans << endl;
}