#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
class CoinCollector {
private:
int N;
vector<vector<int>> grid;
vector<vector<bool>> visited;
ll totalMoves;
ll dfs(int x, int y, int targetX, int targetY) {
if (x == targetX && y == targetY) {
return 0;
}
visited[x][y] = true;
ll minMoves = LLONG_MAX;
vector<pair<int, int>> moves = {
{x+1, y}, {x-1, y}, {x, y+1}, {x, y-1}
};
for (auto [nextX, nextY] : moves) {
if (visited[nextX][nextY]) continue;
ll currentDist = abs(nextX - targetX) + abs(nextY - targetY);
if (currentDist < abs(x - targetX) + abs(y - targetY)) {
ll moves = dfs(nextX, nextY, targetX, targetY);
if (moves != LLONG_MAX) {
minMoves = min(minMoves, moves + 1);
}
}
}
visited[x][y] = false;
return minMoves;
}
public:
ll solve(vector<pair<int, int>>& coins) {
totalMoves = 0;
N = coins.size() / 2;
for (auto& [x, y] : coins) {
if (x < 1) {
totalMoves += 1 - x;
x = 1;
}
if (x > N) {
totalMoves += x - N;
x = N;
}
if (y < 1) {
totalMoves += 1 - y;
y = 1;
}
if (y > 2) {
totalMoves += y - 2;
y = 2;
}
}
visited.resize(N + 2, vector<bool>(3, false));
set<int> usedCoins;
for (int targetX = 1; targetX <= N; targetX++) {
for (int targetY = 1; targetY <= 2; targetY++) {
ll minMoves = LLONG_MAX;
int bestCoin = -1;
for (int i = 0; i < coins.size(); i++) {
if (usedCoins.count(i)) continue;
for (auto& row : visited) {
fill(row.begin(), row.end(), false);
}
ll moves = dfs(coins[i].first, coins[i].second, targetX, targetY);
if (moves < minMoves) {
minMoves = moves;
bestCoin = i;
}
}
totalMoves += minMoves;
usedCoins.insert(bestCoin);
}
}
return totalMoves;
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
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;
}
CoinCollector solver;
cout << solver.solve(coins) << "\n";
return 0;
}
