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

int main() {
  int n;
  long long ans = 0;
  cin >> n;
  vector<long>a(2*n);
  for(int i = 0;i < 2*n;i++){
    cin >> a[i];
  }
  for(int i = 0;i < n;i++){
    long migi,hidari;
    migi = a[a.size()-1]-a[a.size()-2];
    hidari = a[0]-a[1];
    if(migi >= hidari){
      ans += migi;
      a.pop_back();
      a.pop_back();
    }
    else{
      ans += hidari;
      reverse(a.begin(),a.end());
      a.pop_back();
      a.pop_back();
      reverse(a.begin(),a.end());
    }
  }
  cout << ans << endl;
}