#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define x first
#define y second
using namespace std;
using ll = long long;
#define int ll
void umin(int &a, int b) {
a = min(a, b);
}
void umax(int &a, int b) {
a = max(a, b);
}
const int N = 2020;
const int INF = 1e18;
int n;
int x[N];
int y[N];
int p[N];
int w[N];
int dp[N][N];
int f(int i, int fx, int fy) {
return abs(x[i] - fx) + abs(y[i] - fy);
}
signed main() {
#ifdef LC
assert(freopen("input.txt", "r", stdin));
#endif
ios::sync_with_stdio(0), cin.tie(0);
cin >> n;
for (int i = 0; i < 2 * n; ++i) {
cin >> x[i] >> y[i];
p[i] = i;
}
sort(p, p + 2 * n, [&](int i, int j) {
return x[i] < x[j];
});
for (int i = 0; i < 2 * n; ++i) {
w[p[i]] = i;
}
for (int i = 0; i < 2 * n; ++i) {
while (w[i] != i) {
int j = w[i];
swap(w[i], w[j]);
swap(x[i], x[j]);
swap(y[i], y[j]);
}
}
assert(is_sorted(x, x + 2 * n));
fill_n(dp[0], N * N, INF);
dp[0][0] = 0;
for (int i = 0; i <= n; ++i) {
for (int j = 0; j <= n; ++j) {
if (i < n) {
umin(dp[i + 1][j], dp[i][j] + f(i + j, i + 1, 1));
}
if (j < n) {
umin(dp[i][j + 1], dp[i][j] + f(i + j, j + 1, 2));
}
}
}
cout << dp[n][n] << "\n";
return 0;
}
