#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;
typedef long long int ll;

#define x first
#define y second

int main() {

    int n;
    cin >> n;
    vector<pair<int, int>> points(n);
    for (int i=0; i<n; i++){
        cin >> points[i].x >> points[i].y;
    }
    sort(points.begin(), points.end());
    int i=0;
    int result = 0;
    int bestUp = 0; //Y
    int bestDown = 0; //-Y
    int lastx, lastUp, lastDown;
    while (i<n){
        int j=i;
        int maxY = points[i].y;
        int minY = points[i].y;
        while (j < n && points[j].x == points[i].x) {
            maxY = max(maxY, points[j].y);
            minY = min(minY, points[j].y);
            j++;
        }
        if (i == 0) {
            lastx = points[i].x;
            lastUp = maxY;
            lastDown = minY;
        }
        int newUp = points[i].x - lastx + maxY - minY + min(bestUp + abs(lastUp - minY), bestDown + abs(lastDown - minY));
        int newDown = points[i].x - lastx + maxY - minY + min(bestUp + abs(lastUp - maxY), bestDown + abs(lastDown - maxY));

        lastx = points[i].x;
        lastUp = maxY;
        lastDown = minY;
        bestUp = newUp;
        bestDown = newDown;
        i = j;
    }
    cout << min (bestUp, bestDown) << '\n';
}