#include<iostream>
#include<algorithm>
#include<vector>
#include<functional>
#include<string>
#include<cmath>
#include<map>
#include<set>
#include<queue>
#include<stack>
#include<cstdio>
using namespace std;
using ll = long long;
int main(){
  int n;
  cin >> n;
  vector<int> a(2 * n);
  for (int i = 0; i < 2 * n; i++){
    cin >> a[i];
  }
  int left = 0, right = 2 * n - 1;

  ll ans = 0;
  for (int i=0; i<n; i++){
    if(a[left]-a[left+1] > a[right]-a[right-1]){
      if(left > n-2){
        break;
      }
      ans += a[left] - a[left + 1];
      //cout << "l";
      left += 2;
    }else{
      if(right<1){
        break;
      }
      ans += a[right] - a[right - 1];
      //cout << "r" << a[right] << " ";
      right -= 2;
    }
  }
  cout << ans << "\n";
  return 0;
}