#include<bits/stdc++.h>
typedef long long ll;
#define pb push_back
#define fr first
#define sc second
#define endl '\n'
using namespace std;
#define int ll
int n;
int arr[100023][2];
ll ans=0;
const bool boceksizlestir=false;
void f(int left,int right){
if(left==right){
if(arr[left][0]+arr[left][1]<2)return;
if(!arr[left][0]){
ans++;
arr[left][0]++;
arr[left][1]--;
}
if(!arr[left][1]){
ans++;
arr[left][1]++;
arr[left][0]--;
}
if(boceksizlestir){
cout<<left<<":"<<right<<endl;
for(int j=0;j<2;j++){
for(int i=1;i<=n;i++){
cout<<arr[i][j]<<" ";
}
cout<<endl;
}
cout<<endl;
}
return;
}
int mid=(left+right)/2;
int a=0,b=0,ust=0,alt=0,need=0;
function<void(int,int,int,int)>ekle=[&](int from,int tar,int k,int x)->void{
if(x==0)return;
ans+=abs(from-tar)*x;
if(from<=mid)a-=x;
else b-=x;
if(tar<=mid)a+=x;
else b+=x;
if(k)alt+=x;
else ust+=x;
arr[from][k]-=x;
arr[tar][k]+=x;
need-=x;
};
for(int i=left;i<=right;i++){
if(i<=mid)a+=arr[i][0]+arr[i][1];
else b+=arr[i][0]+arr[i][1];
}
f(left,mid);
f(mid+1,right);
if(a>=2*(mid-left+1)&&b>=2*(right-mid)){
return;
}
else if(a>=2*(mid-left+1)){
need=2*(right-mid)-b;
for(int i=mid+1;i<=right;i++){
ust+=arr[i][0];
alt+=arr[i][1];
}
for(int i=mid;i>=left;i--){
if(arr[i][0]-1+arr[i][1]-1>need){
if(alt>ust){
int x=min(min(arr[i][0]-1,alt-ust),need);
ekle(i,mid+1,0,x);
}
else{
int x=min(min(arr[i][1]-1,ust-alt),need);
ekle(i,mid+1,1,x);
}
int x=min(min(arr[i][0]-1,arr[i][1]-1),need/2);
ekle(i,mid+1,0,x);
ekle(i,mid+1,1,x);
if(need){
if(arr[i][0]-1){
ekle(i,mid+1,0,need);
}
else ekle(i,mid+1,1,need);
}
}
else{
int x=arr[i][0]-1;
ekle(i,mid+1,0,x);
x=arr[i][1]-1;
ekle(i,mid+1,1,x);
}
}
for(int i=mid+1;i<=right;i++){
if(arr[i][0]>1&&arr[i][1]==0){
ans++;
arr[i][0]--;
arr[i][1]++;
}
else if(arr[i][1]>1&&arr[i][0]==0){
ans++;
arr[i][1]--;
arr[i][0]++;
}
int x=max(0ll,arr[i][0]-1);
arr[i][0]-=x;
arr[i+1][0]+=x;
x=max(0ll,arr[i][1]-1);
arr[i][1]-=x;
arr[i+1][1]+=x;
}
}
else if(b>=2*(right-mid)){
need=2*(mid-left+1)-a;
for(int i=left;i<=mid;i++){
ust+=arr[i][0];
alt+=arr[i][1];
}
for(int i=mid+1;i<=right;i++){
if(arr[i][0]-1+arr[i][1]-1>need){
if(alt>ust){
int x=min(min(arr[i][0]-1,alt-ust),need);
ekle(i,mid,0,x);
}
else{
int x=min(min(arr[i][1]-1,ust-alt),need);
ekle(i,mid,1,x);
}
int x=min(min(arr[i][0]-1,arr[i][1]-1),need/2);
ekle(i,mid,0,x);
ekle(i,mid,1,x);
if(need){
if(arr[i][0]-1){
ekle(i,mid,0,need);
}
else ekle(i,mid,1,need);
}
}
else{
int x=arr[i][0]-1;
ekle(i,mid,0,x);
x=arr[i][1]-1;
ekle(i,mid,1,x);
}
}
for(int i=mid;i>=left;i--){
if(arr[i][0]>1&&arr[i][1]==0){
ans++;
arr[i][0]--;
arr[i][1]++;
}
else if(arr[i][1]>1&&arr[i][0]==0){
ans++;
arr[i][1]--;
arr[i][0]++;
}
int x=max(0ll,arr[i][0]-1);
ans+=x;
arr[i][0]-=x;
arr[i-1][0]+=x;
x=max(0ll,arr[i][1]-1);
ans+=x;
arr[i][1]-=x;
arr[i-1][1]+=x;
}
}
if(boceksizlestir){
cout<<left<<":"<<right<<endl;
for(int j=0;j<2;j++){
for(int i=1;i<=n;i++){
cout<<arr[i][j]<<" ";
}
cout<<endl;
}
cout<<endl;
}
}
int32_t main(){
ios_base::sync_with_stdio(23^23);cin.tie(NULL);
cin>>n;
for(int i=1;i<=2*n;i++){
pair<int,int>p;cin>>p.fr>>p.sc;
if(p.fr<1){
ans+=1-p.fr;
p.fr=1;
}
if(p.fr>n){
ans+=p.fr-n;
p.fr=n;
}
if(p.sc<1){
ans+=1-p.sc;
p.sc=1;
}
if(p.sc>2){
ans+=p.sc-2;
p.sc=2;
}
arr[p.fr][p.sc-1]++;
}
f(1,n);
cout<<ans<<endl;
}
