#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
const ll MOD2=998244353;
const ll N=2e5+5;
const ld pi=3.14159265359;
const ll INF=(1LL<<60);
typedef pair<ll,pair<ll,pair<ll,pll> > > TY;
#define SQ(i) ((i)*(i))
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()
ll n,x,y,cnt[N][3],lst=1,ans;
pll to(pll A){
if(A.X<1)ans+=abs(A.X-1),A.X=1;
if(A.X>n)ans+=abs(A.X-n),A.X=n;
if(A.Y>2)ans+=abs(A.Y-2),A.Y=2;
if(A.Y<1)ans+=abs(A.Y-1),A.Y=1;
return A;
}
int main(){
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n;
REP1(i,2*n){
cin>>x>>y;
pll nd=to(mp(x,y));
++cnt[nd.X][nd.Y];
}
ll t1=0,t2=0;
REP1(i,n){
t1+=cnt[i][1]-1;
t2+=cnt[i][2]-1;
if(t1*t2<0){
ll tmp=min(abs(t1),abs(t2));
ans+=tmp;
if(t1<0){
t1+=tmp;t2-=tmp;
}else{
t1-=tmp;t2+=tmp;
}
}
ans+=abs(t1)+abs(t2);
}
cout<<ans<<"\n";
return 0;
}
