#include <bits/stdc++.h>
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define uni(v) sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define F first
#define S second
#define pii(x, y) make_pair(x, y)
#define __builtin_popcount __builtin_popcountll
#define __builtin_ctz __builtin_ctzll
#define __builtin_clz __builtin_clzll
#define lg(x) (63 - __builtin_clz(x))
template <class X, class Y>
bool minimize(X &x, const Y &y)
{
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y)
{
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
using namespace std;
typedef long long ll;
const int N = 1e5 + 5;
const int M = 6e5;
const int mod = 1e9 + 7;
const int INF = 1e9 + 7;
const ll oo = 2e18;
const double eps = 1e-1;
int n, c[3][N];
pair<int, int> a[2 * N];
void Input(void)
{
cin >> n;
for (int i = 1; i <= 2 * n; i ++) cin >> a[i].S >> a[i].F;
}
void solve(void)
{
ll ans = 0;
for (int i = 1; i <= 2 * n; i ++)
{
if (a[i].F < 1) ans += 1 - a[i].F, a[i].F = 1;
if (a[i].F > 2) ans += a[i].F - 2, a[i].F = 2;
if (a[i].S < 1) ans += 1 - a[i].S, a[i].S = 1;
if (a[i].S > n) ans += a[i].S - n, a[i].S = n;
c[a[i].F][a[i].S] ++;
}
int row[] = {0, 0, 0};
for (int i = 1; i <= n; i ++)
{
c[1][i] --, c[2][i] --;
row[1] += c[1][i];
row[2] += c[2][i];
if (row[1] < 0 && row[2] > 0)
{
int k = min(-row[1], row[2]);
ans += k;
row[1] += k;
row[2] -= k;
}
else
if (row[1] > 0 && row[2] < 0)
{
int k = min(row[1], -row[2]);
ans += k;
row[1] -= k;
row[2] += k;
}
ans += abs(row[1]) + abs(row[2]);
}
cout << ans;
}
int main()
{
std::ios_base::sync_with_stdio(0); cin.tie(0);
// freopen("CLASSROOM.inp", "r", stdin);
// freopen("CLASSROOM.out", "w", stdout);
int test = 1;
//cin >> test;
while (test --)
{
Input();
solve();
}
return 0;
}
