#include <bits/stdc++.h>
#define ll long long
using namespace std;
struct pt{
ll x, y;
};
ll n,m,k,x,y,z;
ll dp[2 << 21], dig[2 << 21];
pt ar[200005], tar[200005];
void cal(ll x, ll & y) {
while (x) x &= x-1, y++;
}
int dis(pt x, pt y) {
return abs(x.x - y.x) + abs(x.y - y.y);
}
int main() {
cin >> n;
for (int i = 1; i <= n; i++) tar[i] = {i,1};
for (int i = 1; i <= n; i++) tar[i+n] = {i,2};
n *= 2;
for (int i = 1; i <= n; i++) {
cin >> ar[i].x >> ar[i].y;
}
for (int i = 1; i < 1 << n; i++) cal(i,dig[i]);
for (int c = 1; c <= n; c++) {
for (int i = 1; i < 1 << n; i++) {
if (dig[i] != c) continue;
dp[i] = 1e18;
for (int j = 1; j <= n; j++) {
if (~i & (1 << (j-1))) continue;
dp[i] = min(dp[i],dis(tar[c],ar[j]) + dp[i ^ (1 << (j-1))]);
}
}
}
cout << dp[(1 << n) - 1] << "\n";
}
