#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ll long long
#define f first
#define s second
#define int long long
//#define sz(v) int(v.size())
#define all(v) v.begin(),v.end()
int mod = 1e9 + 7;
const int N = 2e5 + 100,k = 317 + 1;
const ll inf = 1e18 + 100;
int mp[N];
void solve(){
int n;
cin >> n;
int x[2 * n + 1],y[2 * n + 1];
ll ans = 0,cnt = 0;
for(int i = 1; i <= 2 * n; i++){
cin >> x[i] >> y[i];
swap(x[i],y[i]);
if(x[i] >= 2){
ans += x[i] - 2;
x[i] = 2;
}
else{
ans += 1 - x[i];
x[i] = 1;
}
}
for(int i = 1; i <= 2 * n; i++){
if(y[i] < 1){
ans += 1 - y[i];
y[i] = 1;
}
else if(y[i] > n){
ans += y[i] - n;
y[i] = n;
}
if(x[i] == 1) cnt++;
mp[y[i]]++;
}
for(int i = 1; i <= n; i++) mp[i] += mp[i - 1];
ans += (n - min(cnt,2 * n - cnt));
cnt = 0;
for(int i = 1; i <= n; i++){
ans += abs(2 * i - mp[i]);
}
cout << ans;
}
signed main(){
//freopen("time.in", "r", stdin);
//freopen("time.out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
int t1 = 1;
while(t1--){
solve();
}
}
