#include <bits/stdc++.h> #define L(i, j, k) for(int i = (j); i <= (k); i++) #define R(i, j, k) for(int i = (j); i >= (k); i--) #define ll long long #define sz(a) ((int) a.size()) #define all(a) a.begin(), a.end() #define vi vector<ll> #define pb emplace_back #define me(a, x) memset(a, x, sizeof(a)) #define fst first #define snd second #define ii pair<ll, ll> using namespace std; const int N=2e5+5; const ll inf=1e18; ll cnt1[N],cnt2[N]; void chmin(ll &a,ll b){ a=min(a,b); } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); int n;cin>>n; vector<ii>v; L(i,0,n*2-1){ int a,b;cin>>a>>b; v.pb(a,b); } vector<ii>v1,v2; L(i,0,n*2-1){ if(llabs(v[i].fst-1)<llabs(v[i].fst-2)){ v1.pb(v[i]); }else v2.pb(v[i]); } sort(all(v1)); sort(all(v2)); ll def1=0,def2=0; ll ans=0; L(i,0,sz(v1)-1){ ll x=v1[i].fst; if(x<1){ cnt1[1]++; ans+=llabs(v1[i].fst-1)+llabs(v1[i].snd-1); } else if(x>n){ cnt1[n]++; ans+=llabs(v1[i].fst-n)+llabs(v1[i].snd-1); } else{ cnt1[v1[i].fst]++; ans+=llabs(v1[i].snd-1); } } L(i,0,sz(v2)-1){ ll x=v2[i].fst; if(x<1){ cnt2[1]++; ans+=llabs(v2[i].fst-n)+llabs(v2[i].snd-1); } else if(x>n){ cnt2[n]++; ans+=llabs(v2[i].fst-n)+llabs(v2[i].snd-1); } else{ cnt1[v2[i].fst]++; ans+=llabs(v2[i].snd-1); } } L(i,1,n){ def1+=cnt1[i]-1; def2+=cnt2[i]-1; if(def1>0&&def2<0){ ll vert=min(def1,-def2); def1-=vert; def2+=vert; ans+=vert; }else if(def1<0&&def2>0){ ll vert=min(-def1,def2); def1+=vert; def2-=vert; ans+=vert; } ans+=abs(def1)+abs(def2); } cout<<ans<<endl; }