#include<iostream>
#include<vector>
using namespace std;

int main() {
	int N, r = 0, l = 0, max = 0;;
	cin >> N;
	vector<int> A(2 * N);
	for (int i = 0;i < 2 * N;i++) {
		cin >> A[i];
	}
	for (int i = 0;i < N;i++) {
		cout << A[2 * l] << A[2 * l + 1] << A[2 * N - 1 - 2 * r] << A[2 * N - 1 - 2 * r - 1] << endl;
		if (A[2 * l] - A[2 * l + 1] >= A[2 * N -1 - 2 * r] - A[2 * N -1 - 2 * r - 1]) {
			max += A[2 * l] - A[2 * l + 1];
			l++;
		}
		else if (A[2 * l] - A[2 * l + 1] < A[2 * N - 1 - 2 * r] - A[2 * N - 1 - 2 * r - 1]) {
			max += A[2 * N - 1 - 2 * r] - A[2 * N - 1 - 2 * r - 1];
			r++;
		}
	}
	cout << max;
}