#include <bits/stdc++.h>
#define ll long long
using namespace std;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n;
cin >> n;
vector<pair<ll,ll>> a(2*n+1);
for (int i=1; i<=2*n; i++) {
cin >> a[i].first >> a[i].second;
}
vector<vector<ll>> freq(n+1, vector<ll>(2));
ll res = 0;
for (int i=1; i<=2*n; i++) {
if (a[i].first>0 && a[i].first<=n) {
if (a[i].second<1) {freq[a[i].first][0]++; res+=abs(a[i].second)+1;}
else if (a[i].second>2) {freq[a[i].first][1]++; res+=abs(a[i].second)-2;}
else freq[a[i].first][a[i].second-1]++;
} else if (a[i].first<1) {
if (a[i].second<1) {freq[1][0]++; res+=(abs(a[i].second)+1+abs(a[i].first)+1);}
else if (a[i].second>2) {freq[1][1]++; res+=(abs(a[i].second)-2+abs(a[i].first)+1);}
else {freq[1][a[i].second-1]++; res+=abs(a[i].first)+1;}
} else {
if (a[i].second<1) {freq[n][0]++; res+=(abs(a[i].first-n)+abs(a[i].second)+1);}
else if (a[i].second>2) {freq[n][1]++; res+=(abs(a[i].first-n)+abs(a[i].second)-2);}
else {freq[n][a[i].second-1]++; res+=abs(a[i].first-n);}
}
}
ll s1 = 0;
ll s2 = 0;
for (int i=1; i<=n; i++) {
if (freq[i][0]==0) s1--;
else s1+=freq[i][0]-1;
if (freq[i][1]==0) s2--;
else s2+=freq[i][1]-1;
if (s1<0 && s2>0) {
ll m = min(abs(s1), s2);
res+=m;
s1+=m;
s2-=m;
} else if (s1>0 && s2<0) {
ll m = min(s1, abs(s2));
res+=m;
s2+=m;
s1-=m;
}
res+=abs(s1)+abs(s2);
}
cout << res;
}
