import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Objects;
import java.util.Scanner;
import java.util.Set;
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 Assignment {
int coin;
Point target;
int distance;
Assignment(int coin, Point target, int distance) {
this.coin = coin;
this.target = target;
this.distance = distance;
}
}
public static int solve(int n, int[] x, int[] y) {
List<Point> sources = new ArrayList<>();
for (int i = 0; i < 2 * n; i++) {
sources.add(new Point(x[i], y[i]));
}
List<Point> targets = new ArrayList<>();
for (int i = 1; i <= n; i++) {
targets.add(new Point(i, 1));
targets.add(new Point(i, 2));
}
List<Assignment> assignments = new ArrayList<>();
for (int i = 0; i < sources.size(); i++) {
for (Point target : targets) {
int distance = manhattanDistance(sources.get(i), target);
assignments.add(new Assignment(i, target, distance));
}
}
assignments.sort((a, b) -> a.distance - b.distance);
boolean[] usedCoins = new boolean[2 * n];
Set<Point> usedTargets = new HashSet<>();
int totalMoves = 0;
int assignedCoins = 0;
for (Assignment assignment : assignments) {
if (assignedCoins == 2 * n) break;
if (!usedCoins[assignment.coin] && !usedTargets.contains(assignment.target)) {
totalMoves += assignment.distance;
usedCoins[assignment.coin] = true;
usedTargets.add(assignment.target);
assignedCoins++;
}
}
return totalMoves;
}
private static int manhattanDistance(Point p1, Point p2) {
return Math.abs(p1.x - p2.x) + Math.abs(p1.y - p2.y);
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int[] x = new int[2 * n];
int[] y = new int[2 * n];
for (int i = 0; i < 2 * n; i++) {
x[i] = sc.nextInt();
y[i] = sc.nextInt();
}
int result = solve(n, x, y);
System.out.println(result);
}
}
