#define _USE_MATH_DEFINES

#include <iostream>
#include <vector>
#include <utility>
#include <climits>
#include <cmath>

using namespace std;

double dist(pair<int, int> a, pair<int, int> b)
{
    long long int x = (a.first - b.first);
    long long int y = (a.second - b.second);
    return sqrt(x * x + y * y);
}

int main()
{
    int N;
    cin >> N;
    vector<pair<int, int>> dots;

    int min_x = 100000000;
    int max_x = -100000000;
    int min_y = 100000000;
    int max_y = -100000000;


    for (int i = 0; i < N; i++) {
        int x, y;
        cin >> x >> y;
        dots.push_back(pair<int, int>{x, y});
        if (x < min_x) {
            min_x = x;
        } else if (x > max_x) {
            max_x = x;
        }
        if (y < min_y) {
            min_y = y;
        } else if (y > max_y) {
            max_y = y;
        }
    }
    vector<pair<int, int>> coords = {{min_x - 1, min_y - 1},
                                     {min_x - 1, max_y + 1},
                                     {max_x + 1, max_y + 1},
                                     {max_x + 1, min_y - 1}};

    vector<pair<int, int>> external = {{INT_MAX, INT_MAX},
                                       {INT_MAX, INT_MAX},
                                       {INT_MAX, INT_MAX},
                                       {INT_MAX, INT_MAX}};
    for (size_t i = 0; i < dots.size(); i++) {
        for (int j = 0; j < 4; j++) {
            if (dist(coords[j], dots[i]) < dist(coords[j], external[j])) {
                external[j] = dots[i];
            }
        }
    }
    double P = (max_x + 1 - min_x + 1) * 2 + (max_y + 1 - min_y + 1) * 2;
    for (int i = 0; i < 4; i++) {
        int a = abs(coords[i].first - external[i].first);
        int b = abs(coords[i].second - external[i].second);
        P = P - 2 * (a + b - 1) + (a + b - 1) * sqrt(2);
    }
    cout << P;
}