#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
using ll = long long;
ll n, x, y, a, b, ans;
vector <ll> A(2e5, 0);
vector <ll> B(2e5, 0);
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n;
for (int i = 0; i < 2 * n; i++) {
cin >> x >> y;
if (x < 1) { ans += 1 - x; x = 1; }
if (x > n) { ans += x - n; x = n; }
if (y <= 1) { ans += 1 - y; A[x]++; }
else { ans += y - 2; B[x]++; }
}
for (int i = 1; i <= n; i++) {
a += A[i] - 1;
b += B[i] - 1;
if (a > 0 && b < 0) {
int k = min(a, -b);
a -= k;
b += k;
ans += k;
}
if (b > 0 && a < 0) {
int k = min(b, -a);
b -= k;
a += k;
ans += k;
}
ans += abs(a);
ans += abs(b);
}
cout << ans;
}
