import java.util.*;
public class joi2019_ho_t4 {
static class Point {
int x, y;
Point(int x, int y) {
this.x = x;
this.y = y;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof Point)) return false;
Point point = (Point) o;
return x == point.x && y == point.y;
}
@Override
public int hashCode() {
return Objects.hash(x, y);
}
}
static class State {
Point position;
int distance;
State(Point position, int distance) {
this.position = position;
this.distance = distance;
}
}
// Directions for possible moves (up, right, down, left)
static int[] dx = {0, 1, 0, -1};
static int[] dy = {1, 0, -1, 0};
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
// Read input
int N = scanner.nextInt();
Point[] coins = new Point[2 * N];
for (int i = 0; i < 2 * N; i++) {
int x = scanner.nextInt();
int y = scanner.nextInt();
coins[i] = new Point(x, y);
}
// Generate target positions (1≤x≤N and 1≤y≤2)
List<Point> targets = new ArrayList<>();
for (int x = 1; x <= N; x++) {
for (int y = 1; y <= 2; y++) {
targets.add(new Point(x, y));
}
}
// Find minimum total distance using Hungarian Algorithm approach
long totalMoves = 0;
boolean[] usedCoins = new boolean[2 * N];
boolean[] usedTargets = new boolean[2 * N];
// For each target position
for (int i = 0; i < 2 * N; i++) {
int minDist = Integer.MAX_VALUE;
int selectedCoin = -1;
int selectedTarget = -1;
// Find the closest unused coin to any unused target
for (int j = 0; j < 2 * N; j++) {
if (usedCoins[j]) continue;
for (int k = 0; k < 2 * N; k++) {
if (usedTargets[k]) continue;
int dist = calculateDistance(coins[j], targets.get(k));
if (dist < minDist) {
minDist = dist;
selectedCoin = j;
selectedTarget = k;
}
}
}
// Mark the coin and target as used and add the distance
usedCoins[selectedCoin] = true;
usedTargets[selectedTarget] = true;
totalMoves += minDist;
}
System.out.println(totalMoves);
}
// Calculate minimum moves between two points using Manhattan distance
private static int calculateDistance(Point start, Point end) {
return Math.abs(start.x - end.x) + Math.abs(start.y - end.y);
}
}
