#include <numeric>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <string.h>
#include <stack>
#include <assert.h>
#include <bitset>
#include <time.h>
#define Endl endl
#define mp make_pair
#define mt make_tuple
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define over(A) {cout<<A<<endl;exit(0);}
#define all(A) A.begin(),A.end()
#define quickcin ios_base::sync_with_stdio(false);
const int mod=1000000007;
const int gmod=3;
const int inf=1039074182;
const double eps=1e-9;
const double pi=3.141592653589793238462643383279;
const ll llinf=2LL*inf*inf;
template <typename T1,typename T2> inline void chmin(T1 &x,T2 b) {if(b<x) x=b;}
template <typename T1,typename T2> inline void chmax(T1 &x,T2 b) {if(b>x) x=b;}
inline void chadd(int &x,int b) {x+=b-mod;x+=(x>>31 & mod);}
template <typename T1,typename T2> inline void chadd(T1 &x,T2 b) {x+=b;if(x>=mod) x-=mod;}
template <typename T1,typename T2> inline void chmul(T1 &x,T2 b) {x=1LL*x*b%mod;}
template <typename T1,typename T2> inline void chmod(T1 &x,T2 b) {x%=b,x+=b;if(x>=b) x-=b;}
template <typename T> inline T mabs(T x) {return (x<0?-x:x);}
using namespace std;
int n;
typedef pair<ll,ll> pll;
vector<pll> U,D;
int t[4];
ll calc(pll x,pll y)
{
return mabs(x.first-y.first)+mabs((ll)x.second-y.second);
}
int cnt[100005][3];
ll res;
int main()
{
// freopen("c.in" ,"r",stdin);
// freopen("c.out","w",stdout);
cin>>n;
for(int i=0;i<n*2;i++)
{
int x,y;
scanf("%d%d",&x,&y);
ll nx=min(max(x,1),n),ny=min(max(y,1),2);
res+=mabs(nx-x)+mabs(ny-y);
cnt[(int)nx][(int)ny]++;
}
for(int i=1;i<=n;i++)
{
cnt[i][1]--;cnt[i][2]--;
if(1LL*cnt[i][1]*cnt[i][2]<0)
{
int tr=min(mabs(cnt[i][1]),mabs(cnt[i][2]));
if(cnt[i][1]<0) cnt[i][1]+=tr;else cnt[i][1]-=tr;
if(cnt[i][2]<0) cnt[i][2]+=tr;else cnt[i][2]-=tr;
res+=tr;
}
cnt[i+1][1]+=cnt[i][1];
cnt[i+1][2]+=cnt[i][2];
res+=mabs(cnt[i][1])+mabs(cnt[i][2]);
}
cout<<res<<endl;
return 0;
}
