#include<iostream>
using namespace std;
typedef long long ll;
const int N=1e5+2;
int n;
ll ans=0;
int fu[N],fd[N];
int plu,pld;
int main(){
ios::sync_with_stdio(false);
cin >> n;
for(int i=1; i<=2*n ;i++){
ll x,y;cin >> x >> y;
ans+=max(0LL,1-x)+max(0LL,x-n);
ans+=max(0LL,1-y)+max(0LL,y-2);
x=min((ll)n,max(1LL,x));
y=min(2LL,max(1LL,y));
if(y==1) fd[x]++;
else fu[x]++;
}
plu=pld=1;
for(int pr=1; pr<=n ;pr++){
while(plu<=pr && fu[pr]>0) ans+=pr-plu++,fu[pr]--;
while(pld<=pr && fd[pr]>0) ans+=pr-pld++,fd[pr]--;
while(plu>pr && pld<=pr && fu[pr]>0) ans+=pr+1-pld++,fu[pr]--;
while(pld>pr && plu<=pr && fd[pr]>0) ans+=pr+1-plu++,fd[pr]--;
ans+=fu[pr];fu[pr+1]+=fu[pr];fu[pr]=0;
ans+=fd[pr];fd[pr+1]+=fd[pr];fd[pr]=0;
}
cout << ans << endl;
}
