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