import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
public class joi2019_ho_t4 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int numOfColumns = scanner.nextInt();
boolean[][] cellsOccupied = new boolean[2][numOfColumns];
for (boolean[] row :
cellsOccupied) {
Arrays.fill(row, false);
}
HashMap<String, Coordinate> coordinatesCoins = new HashMap<>();
int result = 0;
for (int i = 0; i < numOfColumns * 2; i++) {
int x = scanner.nextInt();
int y = scanner.nextInt();
if (x >= 1 && x <= numOfColumns && y >= 1 && y <= 2) {
cellsOccupied[y - 1][x - 1] = true;
} else {
coordinatesCoins.put(x + " " + y, new Coordinate(x, y));
}
}
List<Coordinate> coordinates = new LinkedList<>(coordinatesCoins.values());
for (Coordinate coordinate : coordinates) {
int minimumDistance = Integer.MAX_VALUE;
int minX = 0;
int minY = 0;
Coordinate current = coordinate;
for (int emptySlot = 0; emptySlot < numOfColumns * 2; emptySlot++) {
int coordY = emptySlot % 2;
int coordX = emptySlot / 2;
if (cellsOccupied[coordY][coordX])
continue;
int distance = current.getDistance(coordX + 1, coordY + 1);
if (distance < minimumDistance) {
minX = coordX;
minY = coordY;
minimumDistance = distance;
}
if (minimumDistance == 0)
break;
}
//System.out.println(minimumDistance);
result += minimumDistance;
cellsOccupied[minY][minX] = true;
}
//System.out.println(coordinatesCoins);
System.out.println(result);
}
static class Coordinate {
int x;
int y;
public Coordinate(int x, int y) {
this.x = x;
this.y = y;
}
public int getDistance(int x2, int y2) {
return Math.abs(x - x2) + Math.abs(y - y2);
}
@Override
public String toString() {
return x + " " + y;
}
}
}
