#include <bits/stdc++.h>

using ll = long long;
using namespace std;




struct MinMax{
    ll x;
    ll max, min;
};

map<ll, MinMax> m;


vector<MinMax> v;
unordered_map<int, unordered_map<bool, ll>> results;





ll rec(int i, bool max){
    if(results[i].find(max) != results[i].end())
        return results[i][max];

    if(i + 1 == v.size()) {
        results[i][max] = (v[i].max - v[i].min);
        return results[i][max];
    }
    ll x_dist = i+1 != v.size() ? (v[i+1].x - v[i].x) : 0;
    ll dist_min = rec(i+1, false) + (max ? abs(v[i].max - v[i+1].min) : abs(v[i].min - v[i+1].min)) + x_dist;
    ll dist_max = rec(i + 1, true) + (max ? abs(v[i].max - v[i+1].max) : abs(v[i].min - v[i+1].max)) + x_dist;
    results[i][max] = (v[i].max - v[i].min) + min(dist_min, dist_max);
    return results[i][max];
}


int main() {
    ll n;

    cin >> n;

    for(int i = 0; i < n ;i++){
        ll x, y;
        cin >> x >> y;
        auto found = m.find(x);
        if(found != m.end()){
            //je tam
            found->second.max = max(found->second.max, y);
            found->second.min = min(found->second.min, y);
        }
        else{
            m.insert({x, MinMax{x,y, y}});
        }
    }


    for(auto & i : m) {
        v.emplace_back(i.second);
    }

    cout << min(rec(0, false), rec(0, true)) << endl;

}