#include <bits/stdc++.h>
#ifdef NON_SUBMIT
#define TEST(n) (n)
#define tout cerr
#else
#define TEST(n) ((void)0)
#define tout cin
#endif
using namespace std;
vector<pair<int,int>> P;
multiset<int> S[2];
int X[100000][2];
int main()
{
ios::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
TEST(freopen("input.txt","r",stdin));
TEST(freopen("output.txt","w",stdout));
TEST(freopen("debug.txt","w",stderr));
int N;
long long ans=0;
cin>>N;
P.resize(2*N);
for(auto &[x,y]: P) cin>>x>>y;
sort(P.begin(),P.end());
for(int i=0;i<N;i++) {
ans+=abs(i+1LL-P[2*i].first)+abs(i+1LL-P[2*i+1].first)+abs(1LL-P[2*i].second)+abs(2LL-P[2*i+1].second);
if(P[2*i].second>1) {
auto it=S[0].lower_bound(min(i+1,P[2*i].first));
if(it!=S[0].end()) {
ans-=2;
S[0].erase(it);
}
else S[1].insert(max(i+1,P[2*i].first));
}
if(P[2*i+1].second<2) {
auto it=S[1].lower_bound(min(i+1,P[2*i+1].first));
if(it!=S[1].end()) {
ans-=2;
S[1].erase(it);
}
else S[0].insert(max(i+1,P[2*i+1].first));
}
}
cout<<ans<<'\n';
return 0;
}
