#include <bits/stdc++.h>
#define pb push_back
#define f first
#define sc second
using namespace std;
typedef long long int ll;
typedef string str;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n; cin >> n;
vector<vector<int>> v(2, vector<int>(n, 0));
ll ans = 0;
for(int i = 0; i < 2*n; i++){
ll x, y; cin >> x >> y;
if(x > n) ans+=x-n, x = n;
if(x < 1) ans+=-x+1, x = 1;
if(y > 2) ans+=y-2, y = 2;
if(y < 1) ans+=-y+1, y = 1;
x--, y--;
v[y][x]++;
}
int a = 0, b = 0;
for(int i = 0; i < n; i++){
a+=v[0][i]-1, b+=v[1][i]-1;
if(a > 0 && b < 0){
int mn = min(a, -b);
a-=mn, b+=mn, ans+=mn;
}
else if(b > 0 && a < 0){
int mn = min(-a, b);
a+=mn, b-=mn, ans+=mn;
}
ans+=abs(a)+abs(b);
}
cout << ans << "\n";
}
