//by szh
#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}
const int maxn = 2e5+10;
int n;
int x[maxn],y[maxn];
int cnt[maxn][3];
int main() {
// freopen("input.txt","r",stdin);
std::ios::sync_with_stdio(false);cin.tie(0);
cin>>n;
ll ans = 0;
rep(i,0,2*n) {
cin>>x[i]>>y[i];
if (x[i]<1) ans += 1-x[i],x[i]=1;
if (x[i]>n) ans += x[i]-n,x[i]=n;
if (y[i]<1) ans += 1-y[i],y[i]=1;
if (y[i]>2) ans += y[i]-2,y[i]=2;
cnt[x[i]][y[i]]++;
}
rep(i,1,n+1) {
int cur1 = cnt[i][1],cur2=cnt[i][2];
bool ok=false;
if (cur1>cur2) ok=true,swap(cur1,cur2);
if (cur1<1 and cur2>1) {
int tmp = min(cur2-1,1-cur1);
ans += tmp;
cur1+=tmp,cur2-=tmp;
}
int tmp=1;
if (ok) tmp=2;
cnt[i+1][tmp] += cur1-1;
ans += abs(cur1-1);
tmp=3-tmp;
cnt[i+1][tmp] += cur2-1;
ans += abs(cur2-1);
}
cout<<ans;
return 0;
}
