#include <bits/stdc++.h>

using namespace std;

signed main()
{
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int n, x, y, ret;
    vector<pair<int, int>> volcanoes;

    ret = 0;

    cin >> n;

    while(n--)
    {
        cin >> x >> y;

        volcanoes.push_back(make_pair(x, y));
    }

    sort(volcanoes.begin(), volcanoes.end());

    x = volcanoes[0].first;
    y = volcanoes[0].second;

    for(auto i : volcanoes)
    {
        ret += abs(i.first - x);
        ret += abs(i.second - y);

        x = i.first;
        y = i.second;
    }

    cout << ret << '\n';

    return 0;
}