#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#define ll long long
#define eps 1e-7
#define all(x) ((x).begin()),((x).end())
#define usecppio ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
using pii = pair<int, int>;
#define int ll
vector <int> points[101010];
int n;
int32_t main()
{
usecppio
cin >> n;
for (int i = 0; i<n; i++)
{
int x, y;
cin >> x >> y;
points[y].push_back(x);
}
int ans = 0;
for (int i = 0; i<101010; i++)
{
int s = points[i].size();
if (s<=1)
continue;
else
{
sort(all(points[i]));
for (int j = 1; j<s-1; j++)
{
ans += (min(points[i][j]-points[i][j-1],points[i][j+1]-points[i][j]));
}
ans += points[i][1]-points[i][0];
ans += points[i][s-1]-points[i][s-2];
}
}
cout << ans;
}
