#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
using namespace std;
const int N = 1e5 + 5;
int cnt[N][2];
int val[2];
int n;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
long long ans = 0;
for (int i = 1; i <= 2 * n; i++) {
int x,y;
cin >> x >> y;
if (x > n) {
ans += x - n;
x = n;
}
if (x < 1) {
ans += 1 - x;
x = 1;
}
if (y > 2) {
ans += y - 2;
y = 2;
}
if (y < 1) {
ans += 1 - y;
y = 1;
}
cnt[x][y - 1]++;
}
for (int i = 1; i <= n; i++) {
for (int j = 0; j < 2; j++)
val[j] += cnt[i][j] - 1;
for (int j = 0; j < 2; j++) {
if (val[j] > 0 && val[j ^ 1] < 0) {
int t = min(val[j], -val[j ^ 1]);
ans += t;
val[j] -= t;
val[j ^ 1] += t;
}
}
for (int j = 0; j < 2; j++)
ans += abs(val[j]);
}
cout << ans;
return 0;
}
