#include<bits/stdc++.h>
#pragma optimize ("g",on)
#pragma GCC optimize ("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("03")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
#pragma comment(linker, "/stack:200000000")
//01001101 01100001 01101011 01101000 01100001 01100111 01100001 01111001
using namespace std;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ll long long
#define pb push_back
#define sz(a) a.size()
#define nl '\n'
#define popb pop_back()
#define ld double
#define ull unsigned long long
#define ff first
#define ss second
#define fix fixed << setprecision
#define pii pair<int, int>
#define E exit (0)
#define int long long
const int inf = 1e15, N = 1e6 + 1, mod = 998244353;
vector<pii> dir = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
main() {
//freopen("cowrect.in", "r", stdin);
//freopen("cowrect.out", "w", stdout);
ios_base::sync_with_stdio(NULL);
cin.tie(NULL);
int n;
cin >> n;
vector<pii> a, b;
for (int i = 1, x, y; i <= n * 2; i++) {
cin >> x >> y;
if (y <= 1) {
a.pb({x, y});
}else b.pb({x, y});
}
sort(all(a));
sort(all(b));
if (sz(a) > sz(b)) {
int j = 0, i = 1, ans = 0;
for (; j < sz(a); j++) {
if (i > n) break;
ans += 1 - a[j].ss + abs(i - a[j].ff);
i++;
}
int k = 1;
for (int s = 0; s < sz(b); s++) {
ans += b[s].ss - 2 + abs(k - b[s].ff);
k++;
}
for (; j < sz(a); j++) {
ans += 2 - a[j].ss + abs(k - a[j].ff);
k++;
}
cout << ans;
}else {
int j = 0, i = 1, ans = 0;
for (; j < sz(b); j++) {
if (i > n) break;
ans += b[j].ss - 2 + abs(i - b[j].ff);
i++;
}
int k = 1;
for (int s = 0; s < sz(a); s++) {
ans += 1 - a[s].ss + abs(k - a[s].ff);
k++;
}
for (; j < sz(b); j++) {
ans += a[j].ss - 1 + abs(k - b[j].ff);
k++;
}
cout << ans;
}
}
