#include <iostream>
using namespace std;
long long n, x, y, xx, yy, a[100010][3], ans, c[100010], b[3];
int main() {
cin >> n;
for (int i = 1; i <= 2*n; i++) {
cin >> x >> y;
if (y <= 1) yy = 1;
else yy = 2;
if (x < 1) xx = 1;
else if (x > n) xx = n;
else xx = x;
a[xx][yy]++;
ans += abs(x-xx)+abs(y-yy);
}
for (int i = 1; i <= n; i++) {
c[i] = a[i][1]+a[i][2];
ans += abs(a[i][1]-a[i][2])/2;
if (abs(a[i][1]-a[i][2])%2) {
if (a[i][1] < a[i][2]) b[2]++;
else b[1]++;
}
}
ans += abs(b[2]-b[1])/2;
for (int i = 1; i <= n; i++) {
ans += abs(c[i]-2);
c[i+1] += c[i]-2;
}
cout << ans << endl;
}
