#include <bits/stdc++.h>

using namespace std;
using ll = long long;

#define int ll
int clmp(int a) {
	if(a < 0) return 0;
	return a;
}

int32_t main()
{
	int n;
	cin >> n;
	map<int, pair<int, int>> mp;
	for(int i = 0; i < n; ++i) {
		int x, y;
		cin >> x >> y;
		if(mp.find(x) == mp.end()) {
			mp[x] = {y, y};
		}
		mp[x].first = min(mp[x].first, y);
		mp[x].second = max(mp[x].second, y);
	}
	int pmy = mp.begin()->second.first;
	int pmd = 0;
	int pMy = mp.begin()->second.second;
	int pMd = 0;
	bool fst = true;
	for(auto pp : mp) {
		auto xp = pp.first;
		auto yp = pp.second;
		auto my = yp.first;
		auto My = yp.second;
		int Md = pmd + abs(my - pmy) + abs(My - my);
		Md = min(Md, pMd + abs(my - pMy) + abs(My - my));
		int md = pmd + abs(My - pmy) + abs(my - My);
		md = min(md, pMd + abs(My - pMy) + abs(my - my));
		pmd = md;
		pMd = Md;
		pmy = my;
		pMy = My;
	}

	int r = min(pmd, pMd) + (mp.rbegin()->first - mp.begin()->first);
	cout << r << '\n';

    return 0;
}