#include <bits/stdc++.h>
using namespace std;
#define int long long
#ifdef LOCAL
void debug_out() {cerr<<endl;}
template <typename Head, typename... Tail>
void debug_out(Head _H, Tail... _T) {cerr<<" "<<to_string(_H);debug_out(_T...);}
#define debug(...) cerr<<"["<<#__VA_ARGS__<<"]:",debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif
const int MAXN = 100005;
const int inf=1000000500ll;
const long long oo =1000000000000000500ll;
const int MOD = (int)1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef pair<int,int> pi;
int A[MAXN][3];
int ans;
int32_t main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int n; cin >> n;
for(int i=1;i<=2*n;i++){
int x,y;cin>>x>>y;
int nx,ny;
if(y>=2)ny=2;
else ny=1;
if(x<=1)nx=1;
else if(x<=n)nx=x;
else nx=n;
ans+=abs(x-nx) + abs(y-ny);
A[nx][ny]++;
}
int L=0,R=0;
for(int i=1;i<=n;i++){
L+=A[i][1]-1;
R+=A[i][2]-1;
while(L<0&&R>0){
++L;--R;++ans;
}
while(L>0&&R<0){
--L;++R;++ans;
}
ans+=abs(L)+abs(R);
}
cout<<ans;
}
