/*input
3
0 0
0 4
4 0
2 1
2 5
-1 1
*/
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
ll k[100001][2];
int main()
{
ios_base::sync_with_stdio(false);
ll n;
cin >> n;
ll ans = 0;
for (ll i = 0; i < 2 * n; i++)
{
ll x, y;
cin >> x >> y;
x--;
y--;
if (x < 0)
{
ans += -x;
x = 0;
}
if (x >= n)
{
ans += x - (n - 1);
x = n - 1;
}
if (y < 0)
{
ans += -y;
y = 0;
}
if (y > 1)
{
ans += y - 1;
y = 1;
}
k[x][y]++;
}
for (int x = 0; x < n; x++)
{
if (k[x][0] < 1 && k[x][1] > 1)
{
ll m = min(abs(k[x][0] - 1), abs(k[x][1] - 1));
k[x][0] += m;
k[x][1] -= m;
ans += m;
}
if (k[x][0] > 1 && k[x][1] < 1)
{
ll m = min(abs(k[x][0] - 1), abs(k[x][1] - 1));
k[x][0] -= m;
k[x][1] += m;
ans += m;
}
if (k[x][0] == 0)
{
if (k[x][1] > 1)
{
k[x][1]--;
k[x][0]++;
ans++;
}
}
if (k[x][1] == 0)
{
if (k[x][0] > 1)
{
k[x][0]--;
k[x][1]++;
ans++;
}
}
if (k[x][0] > 1)
{
ans += k[x][0] - 1;
k[x + 1][0] += k[x][0] - 1;
k[x][0] = 1;
}
if (k[x][1] > 1)
{
ans += k[x][1] - 1;
k[x + 1][1] += k[x][1] - 1;
k[x][1] = 1;
}
if (k[x][0] <= 0)
{
ll dx = abs(k[x][0] - 1);
k[x][0] += dx;
k[x + 1][0] -= dx;
ans += dx;
}
if (k[x][1] <= 0)
{
ll dx = abs(k[x][1] - 1);
k[x][1] += dx;
k[x + 1][1] -= dx;
ans += dx;
}
}
cout << ans << "\n";
}
