#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("unroll-loops,Ofast,O3")
#pragma GCC target("avx,avx2,fma")
#define F first
#define S second
#define sz(x) (int)x.size()
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define NFS ios_base::sync_with_stdio(0) , cin.tie(0) , cout.tie(0) ;
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
const int N = 1e5+12;
int n, used[N][4];
long long ans = 0;
int main(){
cin >> n;
for(int i = 1; i <= 2 * n; ++i){
int x, y;
cin >> x >> y;
if(y > 2){
ans += y - 2;
y = 2;
}
if(y < 1){
ans += abs(y-1);
y = 1;
}
if(x > n){
ans += x - n;
x = n;
}
if(x < 1){
ans += abs(x-1);
x = 1;
}
++used[x][y];
}
int cnt1 = 0, cnt2 = 0;
for(int i = 1; i <= n; ++i){
cnt1 += used[i][1] - 1;
cnt2 += used[i][2] - 1;
int mn = min(abs(cnt1), abs(cnt2));
if(cnt1 < 0 && cnt2 > 0){
cnt1 += mn;
cnt2 -= mn;
ans += mn;
}else if(cnt1 > 0 && cnt2 < 0){
cnt2 += mn;
cnt1 -= mn;
ans += mn;
}
ans += abs(cnt1) + abs(cnt2);
}
cout << ans;
}
