#include <bits/stdc++.h>
using namespace std;
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
#ifdef palilo
freopen("in", "r", stdin);
freopen("out", "w", stdout);
#endif
int n;
cin >> n;
int64_t ans = 0;
vector<array<int, 2>> coin(n);
for (int x, y, i = 0; i < 2 * n; ++i) {
cin >> x >> y;
if (x < 1) {
ans += 1 - x, x = 1;
} else if (x > n) {
ans += x - n, x = n;
}
if (y < 1) {
ans += 1 - y, y = 1;
} else if (y > 2) {
ans += y - 2, y = 2;
}
++coin[x - 1][y - 1];
}
array<int, 2> cnt {};
for (int i = 0; i < n; ++i) {
cnt[0] += coin[i][0] - 1, cnt[1] += coin[i][1] - 1;
if (cnt[0] < 0 && cnt[1] > 0) {
const int borrow = min(-cnt[0], cnt[1]);
cnt[0] += borrow, cnt[1] -= borrow;
ans += borrow;
}
if (cnt[1] < 0 && cnt[0] > 0) {
const int borrow = min(-cnt[1], cnt[0]);
cnt[1] += borrow, cnt[0] -= borrow;
ans += borrow;
}
ans += abs(cnt[0]) + abs(cnt[1]);
}
cout << ans;
}
