import java.util.Scanner;
public class joi2019_ho_t4 {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int numberOfRows = scanner.nextInt();
long[][] coinCoordinates = new long[2 * numberOfRows][2];
for (int index = 0; index < 2 * numberOfRows; index++) {
coinCoordinates[index][0] = scanner.nextLong();
coinCoordinates[index][1] = scanner.nextLong();
}
System.out.println(calculateMinimumMoves(numberOfRows, coinCoordinates));
scanner.close();
}
public static long calculateMinimumMoves(int numberOfRows, long[][] coinCoordinates) {
Position[] coinPositions = new Position[2 * numberOfRows];
Position[] targetPositions = new Position[2 * numberOfRows];
for (int index = 0; index < 2 * numberOfRows; index++) {
coinPositions[index] = new Position(coinCoordinates[index][0], coinCoordinates[index][1]);
}
int targetIndex = 0;
for (int row = 1; row <= numberOfRows; row++) {
targetPositions[targetIndex++] = new Position(row, 1);
targetPositions[targetIndex++] = new Position(row, 2);
}
boolean[] isTargetUsed = new boolean[2 * numberOfRows];
long totalDistance = 0;
for (int coinIndex = 0; coinIndex < 2 * numberOfRows; coinIndex++) {
long minimumDistance = Long.MAX_VALUE;
int optimalTargetIndex = -1;
for (int targetIndexInner = 0; targetIndexInner < 2 * numberOfRows; targetIndexInner++) {
if (!isTargetUsed[targetIndexInner]) {
long currentDistance = calculateManhattanDistance(coinPositions[coinIndex], targetPositions[targetIndexInner]);
if (currentDistance < minimumDistance) {
minimumDistance = currentDistance;
optimalTargetIndex = targetIndexInner;
}
}
}
isTargetUsed[optimalTargetIndex] = true;
totalDistance += minimumDistance;
}
return totalDistance;
}
public static long calculateManhattanDistance(Position from, Position to) {
return Math.abs(from.x - to.x) + Math.abs(from.y - to.y);
}
static class Position {
long x;
long y;
Position(long x, long y) {
this.x = x;
this.y = y;
}
}
}
