import java.util.*;
public class joi2019_ho_t4 {
public static int minTotalMoves(int n, List<int[]> coins) {
List<int[]> targets = new ArrayList<>();
for (int x = 1; x <= n; x++) {
for (int y = 1; y <= 2; y++) {
targets.add(new int[]{x, y});
}
}
coins.sort(Comparator.comparingInt((int[] coin) -> coin[0]).thenComparingInt(coin -> coin[1]));
targets.sort(Comparator.comparingInt((int[] target) -> target[0]).thenComparingInt(target -> target[1]));
int[][] cost = new int[2 * n][2 * n];
for (int i = 0; i < 2 * n; i++) {
for (int j = 0; j < 2 * n; j++) {
cost[i][j] = Math.abs(coins.get(i)[0] - targets.get(j)[0]) + Math.abs(coins.get(i)[1] - targets.get(j)[1]);
}
}
int maxState = (int) Math.pow(3, 2 * n);
int[] dp = new int[maxState];
Arrays.fill(dp, Integer.MAX_VALUE);
dp[0] = 0;
for (int mask = 0; mask < maxState; mask++) {
int[] assigned = new int[2 * n];
int currentMask = mask;
for (int i = 0; i < 2 * n; i++) {
assigned[i] = currentMask % 3;
currentMask /= 3;
}
int x = 0;
for (int i = 0; i < 2 * n; i++) {
if (assigned[i] != 0) {
x++;
}
}
if (x >= 2 * n) {
continue;
}
for (int j = 0; j < 2 * n; j++) {
if (assigned[j] == 0) {
for (int newTarget = 1; newTarget <= 2; newTarget++) {
int newMask = mask + newTarget * (int) Math.pow(3, j);
dp[newMask] = Math.min(dp[newMask], dp[mask] + cost[x][j]);
}
}
}
}
return dp[maxState - 1];
}
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int n = Integer.parseInt(scanner.nextLine());
List<int[]> coins = new ArrayList<>();
for (int i = 0; i < 2 * n; i++) {
String[] parts = scanner.nextLine().split(" ");
coins.add(new int[]{Integer.parseInt(parts[0]), Integer.parseInt(parts[1])});
}
System.out.println(minTotalMoves(n, coins));
scanner.close();
}
}
