#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
map<int, pair<int,int>>m;
int dist(int x, int y, int u, int v){
    return abs(x-u)+abs(y-v);
}
int main(){
    long long sum=0;
    int cnt, x,y;
    cin >> cnt;
    while(cnt--){
        cin >> x >> y;
        if(m.find(x)!=m.end())
            m[x] = {min(m[x].first, y), max(m[x].second, y)};
        else m[x] = {y,y};
    }
    set<int> s;
    int ss=0,nylast,ylast=-1,mi,tfirst = -2;
    for(auto it1=m.begin(), it2=next(m.begin());it2!=m.end();++it1,++it2){
        mi = dist(it1->first,it1->second.first, it2->first,it2->second.first);
        tfirst = it1->second.first;
        nylast = it2->second.first;

        if(mi > dist(it1->first,it1->second.second, it2->first,it2->second.first)){
            tfirst = it1->second.second;
            nylast = it2->second.first;
            mi = dist(it1->first,it1->second.second, it2->first,it2->second.first);
        }
        if(mi > dist(it1->first,it1->second.first, it2->first,it2->second.second)){
            tfirst = it1->second.first;
            nylast = it2->second.second;
            mi = dist(it1->first,it1->second.first, it2->first,it2->second.second);
        }
        if(mi > dist(it1->first,it1->second.second, it2->first,it2->second.second)){
            tfirst = it1->second.second;
            nylast = it2->second.second;
            mi = dist(it1->first,it1->second.second, it2->first,it2->second.second);
        }
        if(ylast == tfirst) s.insert(ss);
        sum+=mi;
        ylast = nylast;
        ++ss;
    }
    ss=0;
    for(auto&x:m){
        sum+=(s.count(ss))*abs(x.second.first-x.second.second)+abs(x.second.first-x.second.second);
        ++ss;
    }

    cout << sum << "\n";
}