#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define mp make_pair
#define eb emplace_back
#define pb push_back
#define pii pair<int,int>
#define X first
#define Y second
#define all(x) x.begin(), x.end()
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T i, U ...j) {
cout << i << ' ', abc(j...);
}
template <typename T> void printv(T l, T r) {
for (; l != r; ++l)
cout << *l << " \n"[l + 1 == r];
}
#ifdef Doludu
#define test(x...) abc("[" + string(#x) + "]", x)
#define owo freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#else
#define test(x...) void(0)
#define owo ios::sync_with_stdio(false), cin.tie(0)
#endif
int main () {
owo;
int n;
cin >> n;
vector <vector <int>> cnt(n, vector <int> (2, 0));
lli ans = 0;
for (int i = 0, x, y; i < n * 2; ++i) {
cin >> x >> y, --x, --y;
if (x < 0) {
if (y <= 0)
ans += -x - y, cnt[0][0]++;
else
ans += -x + y - 1, cnt[0][1]++;
} else if (x >= n) {
if (y <= 0)
ans += x - n + 1 - y, cnt[n - 1][0]++;
else
ans += x - n + 1 + y - 1, cnt[n - 1][1]++;
} else {
if (y <= 0)
ans += -y, cnt[x][0]++;
else
ans += y - 1, cnt[x][1]++;
}
}
vector <pii> source;
for (int i = 0; i < n; ++i) for (int j = 0; j < 2; ++j) {
for (int k = 0; k < cnt[i][j]; ++k)
source.eb(i, j);
}
vector <vector <lli>> dp(n + 1, vector <lli> (n + 1, 1ll << 60));
dp[0][0] = 0;
for (int d = 0; d < 2 * n; ++d) for (int i = 0; i <= n; ++i) {
int j = d - i;
if (j < 0 || j > n)
continue;
if (i + 1 <= n)
dp[i + 1][j] = min(dp[i + 1][j], dp[i][j] + abs(source[d].X - i) + abs(source[d].Y - 1));
if (j + 1 <= n)
dp[i][j + 1] = min(dp[i][j + 1], dp[i][j] + abs(source[d].X - j) + abs(source[d].Y));
}
cout << ans + dp[n][n] << '\n';
}
