#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
long long manhattanDistance(int x1, int y1, int x2, int y2) {
return abs(x1 - x2) + abs(y1 - y2);
}
int main() {
int N;
cin >> N;
vector<pair<int, int>> coins(2 * N);
for (int i = 0; i < 2 * N; i++) {
cin >> coins[i].first >> coins[i].second;
}
vector<pair<int, int>> targets;
for (int x = 1; x <= N; x++) {
targets.push_back({x, 1});
targets.push_back({x, 2});
}
sort(coins.begin(), coins.end());
sort(targets.begin(), targets.end());
long long total_cost = 0;
for (int i = 0; i < 2 * N; i++) {
total_cost += manhattanDistance(coins[i].first, coins[i].second, targets[i].first, targets[i].second);
}
cout << total_cost << endl;
return 0;
}
