#include <bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); i++)
#define R(i, j, k) for(int i = (j); i >= (k); i--)
#define ll long long
#define sz(a) ((int) a.size())
#define all(a) a.begin(), a.end()
#define vi vector<ll>
#define pb emplace_back
#define me(a, x) memset(a, x, sizeof(a))
#define fst first
#define snd second
#define ii pair<ll, ll>
using namespace std;
const int N=2e5+5;
const ll inf=1e18;
ll cnt1[N],cnt2[N];
void chmin(ll &a,ll b){
a=min(a,b);
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;cin>>n;
vector<ii>v;
L(i,0,n*2-1){
int a,b;cin>>a>>b;
v.pb(a,b);
}
vector<ii>v1,v2;
L(i,0,n*2-1){
if(llabs(v[i].snd-1)<=llabs(v[i].snd-2)){
v1.pb(v[i]);
}else v2.pb(v[i]);
}
sort(all(v1));
sort(all(v2));
ll def1=0,def2=0;
ll ans=0;
L(i,0,sz(v1)-1){
ll x=v1[i].fst;
if(x<1){
cnt1[1]++;
ans+=llabs(v1[i].fst-1)+llabs(v1[i].snd-1);
}
else if(x>n){
cnt1[n]++;
ans+=llabs(v1[i].fst-n)+llabs(v1[i].snd-1);
}
else{
cnt1[v1[i].fst]++;
ans+=llabs(v1[i].snd-1);
}
}
L(i,0,sz(v2)-1){
ll x=v2[i].fst;
if(x<1){
cnt2[1]++;
ans+=llabs(v2[i].fst-1)+llabs(v2[i].snd-2);
}
else if(x>n){
cnt2[n]++;
ans+=llabs(v2[i].fst-n)+llabs(v2[i].snd-2);
}
else{
cnt2[v2[i].fst]++;
ans+=llabs(v2[i].snd-2);
}
}
L(i,1,n){
def1+=cnt1[i]-1;
def2+=cnt2[i]-1;
if(def1>0&&def2<0){
ll vert=min(def1,-def2);
def1-=vert;
def2+=vert;
ans+=vert;
}else if(def1<0&&def2>0){
ll vert=min(-def1,def2);
def1+=vert;
def2-=vert;
ans+=vert;
}
ans+=abs(def1)+abs(def2);
}
cout<<ans<<endl;
}
