#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N = 1e5;
struct xy{
ll x,y;
}v[N*2];
ll f[N][2];
ll f2[2];
int main(){
ll n;
ll ans = 0;
cin>>n;
for(ll i = 0;i < 2*n;i++){
cin>>v[i].x>>v[i].y;
v[i].x--;v[i].y--;
if(0 > v[i].x || v[i].x > n - 1){
ans+=min(abs(v[i].x - 0),abs(v[i].x - (n - 1)));
}
ans+=min(abs(v[i].y - 0),abs(v[i].y - 1));
v[i].x = max(v[i].x,0ll);
v[i].y = max(v[i].y,0ll);
v[i].x = min(v[i].x,n - 1);
v[i].y = min(v[i].y,1ll);
f[v[i].x][v[i].y]++;
}
for(int i = 0;i < n;i++){
f2[0]+=f[i][0];
f2[1]+=f[i][1];
f2[0]--;
f2[1]--;
if(f2[0] > 0 && f2[1] < 0){
int x = min(f2[0],-f2[1]);
f2[0]-=x;
f2[1]+=x;
ans+=x;
}
if(f2[0] < 0 && f2[1] > 0){
int x = min(-f2[0],f2[1]);
f2[0]+=x;
f2[1]-=x;
ans+=x;
}
if(i != n - 1){
ans+=abs(f2[1]);
ans+=abs(f2[0]);
}
}
cout<<ans<<'\n';
return 0;
}
