#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
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;
}
sort(coins.begin(), coins.end());
long long total = 0;
for (int i = 0; i < n; ++i) {
int x = i + 1;
pair<int, int> coin1 = coins[2 * i];
pair<int, int> coin2 = coins[2 * i + 1];
int h_cost = abs(coin1.first - x) + abs(coin2.first - x);
int y1 = coin1.second;
int y2 = coin2.second;
int option1 = abs(y1 - 1) + abs(y2 - 2);
int option2 = abs(y1 - 2) + abs(y2 - 1);
int v_cost = min(option1, option2);
total += h_cost + v_cost;
}
cout << total << endl;
return 0;
}
