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

typedef long long ll;
typedef pair<int, int> P;

#define mod 1000000007
#define inf 1000000000
#define all(x) (x).begin(), (x).end()
#define pb push_back

const long double PI = acos(-1);

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

int main(){
  ll n;
  cin >> n;
  vector<ll> a(2*n);
  for(ll i = 0; i < 2*n; i++) cin >> a[i];

  ll ans = 0;
  ll left = 0, right = 2*n-1;
  n *= 2;
  while(n){
    ll leftscore = a[left] - a[left+1];
    ll rightscore = a[right] - a[right-1];

    if(leftscore > rightscore){
      ans += leftscore;
      left += 2;
      n -= 2;
    }else{
      ans += rightscore;
      right -= 2;
      n -= 2;
    }
  }
  cout << ans << endl;
  return 0;
}