#include<bits/stdc++.h>
#define pb push_back
#define pf push_front
#define F first
#define S second
#define ff first
#define ss second
#define ll long long
#define ull unsigned long long
#define ld long double
#define pll pair<ll,ll>
#define plll pair<ll,pll>
#define pllll pair<pll,pll>
#define vl vector<ll>
#define vll vector<pll>
#define vlll vector<plll>
#define vllll vector<pllll>
#define vb vector<bool>
#define sz size()
#define fr front()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define bk back();
using namespace std;
const ld pi=3.14159265359;
const ll e5=1e5;
const ll e6=1e6;
const ll e9=1e9;
const ll inf=1e18;
const ll mod=1e9+7;
const ll mod2=998244353;
const ll N=1e5+5;
ll bpm(ll x,ll y,ll m){if(y==0)return 1%m;if(y==1)return x%m;ll p=bpm(x,y/2,m);
if(y%2==0)return p*p%m;else return p*p%m*x%m;}
ll bp(ll x,ll y){if(y==0)return 1;if(y==1)return x;ll p=bp(x,y/2);
if(y%2==0)return p*p;else return p*p*x;}
ll cnt[N][3];
void solve(/**/){
ll n,ans=0;
cin>>n;
for(ll i=1;i<=n+n;i++){
ll x,y; cin>>x>>y;
if(x>n) ans+=x-n, x=n;
else if(x<1) ans+=1-x, x=1;
if(y>2) ans+=y-2,y=2;
else if(y<1) ans+=1-y, y=1;
cnt[x][y]++;
}
ll a=0,b=0;
for(ll i=1;i<=n;i++){
a+=cnt[i][1]-1, b+=cnt[i][2]-1;
while(a>0&&b<0) a--, b++, ans++;
while(b>0&&a<0) b--, a++, ans++;
ans+=abs(a)+abs(b);
}
cout<<ans;
return;
}
int main(/*Aldk*/){
ios_base::sync_with_stdio(false);cin.tie(NULL);
//freopen(".in", "r", stdin);
//freopen(".out", "w", stdout);
//cout<<setprecision(6)<<fixed;
ll T=1;
//cin>>T;
for(ll i=1;i<=T;i++){
//cout<<"Case #"<<i<<": ";
solve();
//cout<<'\n';
}
return 0;
}
