import java.util.*;
public class joi2019_ho_t4 {
static class Position {
long x, y;
Position(long x, long y) {
this.x = x;
this.y = y;
}
}
private static long calculateDistance(Position from, Position to) {
return Math.abs(from.x - to.x) + Math.abs(from.y - to.y);
}
public static long minMovesToTarget(int N, long[][] coins) {
Position[] coinPositions = new Position[2 * N];
Position[] targets = new Position[2 * N];
// Crear posiciones de monedas
for (int i = 0; i < 2 * N; i++) {
coinPositions[i] = new Position(coins[i][0], coins[i][1]);
}
// Crear posiciones objetivo
int idx = 0;
for (int x = 1; x <= N; x++) {
targets[idx++] = new Position(x, 1);
targets[idx++] = new Position(x, 2);
}
boolean[] usedTarget = new boolean[2 * N];
long totalMoves = 0;
// Para cada moneda
for (int i = 0; i < 2 * N; i++) {
long minDist = Long.MAX_VALUE;
int bestTarget = -1;
// Encontrar el objetivo más cercano no usado
for (int j = 0; j < 2 * N; j++) {
if (!usedTarget[j]) {
long dist = calculateDistance(coinPositions[i], targets[j]);
if (dist < minDist) {
minDist = dist;
bestTarget = j;
}
}
}
usedTarget[bestTarget] = true;
totalMoves += minDist;
}
return totalMoves;
}
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int N = scanner.nextInt();
long[][] coins = new long[2 * N][2];
for (int i = 0; i < 2 * N; i++) {
coins[i][0] = scanner.nextLong();
coins[i][1] = scanner.nextLong();
}
System.out.println(minMovesToTarget(N, coins));
scanner.close();
}
}
