#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ff first
#define ss second
#define vl vector<long long>
#define vi vector<int>
#define pii pair<int,int>
#define pll pair<long long, long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
//mt19937 mt;void random(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll rand(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
int arr[100'001][3];
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//random();
int n;
cin >> n;
ll ans = 0;
rep2(i,1,n) rep2(j,0,1) arr[i][j] = -1;
rep(i,n*2)
{
ll x,y;
cin >> x >> y;
if(x < 1)
{
ans += (1-x);
x = 1;
}
if(x > n)
{
ans += (x-n);
x = n;
}
if(y < 1)
{
ans += (1-y);
y = 1;
}
if(y > 2)
{
ans += (y-2);
y = 2;
}
arr[x][y-1]++;
}
rep2(i,1,n)
{
// cout << arr[i][0] << " " << arr[i][1] << " arr\n";
if(arr[i][0] <= -1)
{
if(arr[i][1] >= 1)
{
ll od = min(-arr[i][0],arr[i][1]);
arr[i][1]-=od;
arr[i][0]+=od;
ans+=od;
}
}
if(arr[i][1] <= -1)
{
if(arr[i][0] >= 1)
{
ll od = min(-arr[i][1],arr[i][0]);
arr[i][0]-=od;
arr[i][1]+=od;
ans+=od;
}
}
arr[i+1][0] += arr[i][0];
arr[i+1][1] += arr[i][1];
ans += abs(arr[i][0]) + abs(arr[i][1]);
}
cout << ans;
}
