#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
typedef long long ll;
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
struct Point {
ll x, y;
};
bool operator<(Point a, Point b) {
return a.x < b.x;
}
ll dist(Point a, Point b) {
return abs(a.x-b.x) + abs(a.y-b.y);
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n;
cin >> n;
ll ans = 0;
vector<Point> pkt;
for(int i=0; i<2*n; ++i) {
Point p; cin >> p.x >> p.y;
if(p.y > 1) {
ans += p.y-2;
p.y = 2;
} else {
ans += 1-p.y;
p.y = 1;
}
pkt.push_back(p);
}
sort(pkt.begin(), pkt.end());
for(int i=n; i>=1; --i) {
Point p1 = pkt.back(); pkt.pop_back();
Point p2 = pkt.back(); pkt.pop_back();
ll d1 = dist(p1, {i, 1})+dist(p2, {i, 2});
ll d2 = dist(p1, {i, 2})+dist(p2, {i, 1});
ans += min(d1, d2);
}
cout << ans << "\n";
return 0;
}
