#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#define int long long
#define ll long long
#define ull unsigned ll
#define db double
#define ldb long db
#define mp make_pair
#define fi first
#define se second
#define pii pair<int,int>
#define pbI push_back
#define inf 1e18
#define mdI int mid=(l+r)>>1
#define lowbit(x) ((x)&(-(x)))
#define ppc(x) __builtin_popcount(x)
#define rep(a,b,c) for(signed a=b;a<=c;a++)
#define vep(a,b,c) for(int a=b;a>=c;a--)
#define MAXN 520
#define gint __int128
#define MOD 1000000009//998244353
int qread(){
	char o=getchar();int f=1,x=0;
	for(;!isdigit(o);o=getchar())if(o=='-')f*=-1;
	for(;isdigit(o);o=getchar())x=x*10+o-'0';
	return f*x;
}
ll qp(ll a,ll b,ll p=MOD){
    ll bs=a,rs=1;while(b){if(b&1)rs=rs*bs%p;bs=bs*bs%p;b>>=1;}return rs;
}
template<typename T> void chmx(T &x,T y){if(y>x)x=y;}
template<typename T> void chmi(T &x,T y){if(y<x)x=y;}
template<typename T> void chmd(T &x,T y,T m=MOD){x=(x+y)%MOD;}
//void chmd(ll &x,ll y,ll m=MOD){x=(x+y)%m;}
bool FLA;
int n;
int X[MAXN],Y[MAXN];
int mix[MAXN][MAXN],miy[MAXN][MAXN];
int dp[MAXN][MAXN];
bool FLB;
signed main(){
    cerr<<((&FLB)-(&FLA))/1024.0/1024<<endl;
    cin>>n;n++;
    X[1]=Y[1]=0;rep(i,2,n)X[i]=qread(),Y[i]=qread();
    rep(i,1,n){
        mix[i][i-1]=miy[i][i-1]=inf;
        rep(j,i,n){
            mix[i][j]=min(mix[i][j-1],X[j]);
            miy[i][j]=min(miy[i][j-1],Y[j]);
        }
    }
    memset(dp,0x3f,sizeof(dp));
    rep(len,1,n){
        for(int i=1,j=len;j<=n;i++,j++){
            if(len==1){dp[i][j]=0;}
            rep(k,i,j-1){
                chmi(dp[i][j],dp[i][k]+dp[k+1][j]+abs(mix[i][k]-mix[k+1][j])+abs(miy[i][k]-miy[k+1][j]));
            }
        }
    }
    cout<<dp[1][n];
}
/*
类树，根在min
*/