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


int main(){
  long n;
  cin >> n;
  vector<long> v(2*n);

  for(int i = 0; i < 2*n; i++){
    cin >> v.at(i);
  }

  int left = 0;
  int right = 2 * n -1;
  long score = 0;

  for(int i = 0; i < n; i++){
    long l = v.at(left) - v.at(left + 1);
    long r = v.at(right) - v.at(right -1);

    if(r >= l){
      score += r;
      right -= 2;
    } else {
      score += l;
      left += 2;
    }
  }
  cout << score << endl;

}