import java.util.*;
public class joi2019_ho_t4 {
static class Position {
long x, y;
// O(1)
Position(long x, long y) {
this.x = x;
this.y = y;
}
}
// O(1)
private static long calculateDistance(Position from, Position to) {
return Math.abs(from.x - to.x) + Math.abs(from.y - to.y); // 6 oe
}
// T(n) = 12 + 2N(9) + 5 + N(13) + 9 + 2N(9 + 2N(14) + 4 + 2 + 2) + 1
// T(n) = 27 + 18N + 13N + 2N(17 + 28N)
// T(n) = 27 + 31N + 34N + 56N^2
// O(N^2)
public static long minMovesToTarget(int N, long[][] coins) {
Position[] coinPositions = new Position[2 * N]; // 4 oe
Position[] targets = new Position[2 * N]; // 4 oe
for (int i = 0; i < 2 * N; i++) {
// 2 oe + 2 oe + 2 oe
coinPositions[i] = new Position(coins[i][0], coins[i][1]); // 5 oe
}
int idx = 0; // 2 oe
for (int x = 1; x <= N; x++) {
// 2 oe + 1 oe + 2 oe
targets[idx++] = new Position(x, 1); // 5 oe
targets[idx++] = new Position(x, 2); // 5 oe
}
boolean[] usedTarget = new boolean[2 * N]; // 3 oe
long totalMoves = 0; // 2 oe
for (int i = 0; i < 2 * N; i++) {
// 2 oe + 2 oe + 2 oe
long minDist = Long.MAX_VALUE; // 2 oe
int bestTarget = -1; // 2 oe
for (int j = 0; j < 2 * N; j++) {
// 2 oe + 2 oe + 2 oe
if (!usedTarget[j]) { // 2 oe
long dist = calculateDistance(coinPositions[i], targets[j]); // 5 oe
if (dist < minDist) { // 1 oe
minDist = dist; // 1 oe
bestTarget = j; // 1 oe
}
}
}
usedTarget[bestTarget] = true; // 2 oe
totalMoves += minDist; // 2 oe
}
return totalMoves; // 1 oe
}
// T(n) = 9 + 2 + 2 + 2N(6 + 4) + 1 + N^2 + 1
// T(n) = 15 + 20N + N^2
// T(n) = 15 + 20N + N^2
// O(N^2)
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in); // 3 oe
int N = scanner.nextInt(); // 3 oe
long[][] coins = new long[2 * N][2]; // 3 oe
for (int i = 0; i < 2 * N; i++) {
// 2 oe + 2 oe + 2 oe
coins[i][0] = scanner.nextLong(); // 3 oe
coins[i][1] = scanner.nextLong(); // 3 oe
}
System.out.println(minMovesToTarget(N, coins)); // 1 oe + O(N^2)
scanner.close(); // 1 oe
}
}
