#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, 1, -1};
ll bfs(ll startX, ll startY, ll n) {
if (startX >= 1 && startX <= n && startY >= 1 && startY <= 2) {
return 0;
}
ll x = startX;
ll y = startY;
ll moves = 0;
if (x < 1) {
moves += (1 - x);
x = 1;
} else if (x > n) {
moves += (x - n);
x = n;
}
if (y < 1) {
moves += (1 - y);
y = 1;
} else if (y > 2) {
moves += (y - 2);
y = 2;
}
return moves;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
vector<vector<int>> coins(n + 1, vector<int>(3, 0));
ll totalMoves = 0;
for (int i = 0; i < 2 * n; i++) {
ll x, y;
cin >> x >> y;
totalMoves += bfs(x, y, n);
if (x >= 1 && x <= n && y >= 1 && y <= 2) {
coins[x][y]++;
}
}
for (int i = 1; i <= n; i++) {
coins[i][1]--;
coins[i][2]--;
if (coins[i][1] > 0 && coins[i][2] < 0) {
int moves = min(coins[i][1], -coins[i][2]);
totalMoves += moves;
coins[i][1] -= moves;
coins[i][2] += moves;
} else if (coins[i][2] > 0 && coins[i][1] < 0) {
int moves = min(coins[i][2], -coins[i][1]);
totalMoves += moves;
coins[i][2] -= moves;
coins[i][1] += moves;
}
if (i < n) {
coins[i + 1][1] += coins[i][1];
coins[i + 1][2] += coins[i][2];
}
totalMoves += abs(coins[i][1]) + abs(coins[i][2]);
}
cout << totalMoves << "\n";
return 0;
}
