#include<bits/stdc++.h>
using namespace std;
using ll = long long;

#define fo(a,b) for(int a=0;a<(b);a++)

const int MAX = 12345678;

pair<int, int> in[1123456];
int n;
int main()
{
	scanf("%d", &n);
	fo(i,n)
		scanf("%d%d", &(in[i].first), &(in[i].second));
	sort(in, in+n);
	int last_minim=MAX;
	int last_maxim=MAX;
	ll last_minim_opt, last_maxim_opt;
	int minim=MAX, maxim=-MAX;
	fo(i,n)
	{
		minim = min(minim, in[i].second);
		maxim = max(maxim, in[i].second);
		if(i==n-1 || in[i].first != in[i+1].first)
		{
			ll maxim_opt = abs(minim-maxim);
			ll minim_opt = abs(minim-maxim);
			if(last_minim!=MAX)
			{
				maxim_opt += min(
						abs(minim-last_minim)+last_minim_opt,
						abs(minim-last_maxim)+last_maxim_opt);
				minim_opt += min(
						abs(maxim-last_minim)+last_minim_opt,
						abs(maxim-last_maxim)+last_maxim_opt);
			}
			last_minim = minim;
			last_maxim = maxim;
			minim=MAX; maxim=-MAX;
			last_minim_opt = minim_opt;
			last_maxim_opt = maxim_opt;
		}
	}
	printf("%lld\n", min(last_minim_opt, last_maxim_opt)+abs(in[0].first-in[n-1].first));
	return 0;
}