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

signed main(){
  lint N; cin >> N;
  vector<lint> a(2*N);
  for(lint i = 0; i < a.size(); i++) cin >> a[i];
  lint ans = 0;
  for(lint i = 0; i < N; i++){
    lint n = a.size();
    lint p = a[0] - a[1];
    lint q = a[n - 1] - a[n - 2];
    if(p > q){
      a.erase(a.begin()); a.erase(a.begin());
      ans += p;
    } 
    if(p <= q){
      a.erase(a.begin() + n - 1); a.erase(a.begin() + n - 2);
      ans += q;
    }
  }
  cout << ans << endl;
}