#include<bits/stdc++.h>

 #define LL long long

 #define N 100005

 #define lowbit(x) x&(-x)

 using namespace std;

 inline int ra()

 {

     int x=,f=; char ch=getchar();

     while (ch<'' || ch>'') {if (ch=='-') f=-; ch=getchar();}

     while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();}

     return x*f;

 }

 const LL INF=1e16;

 LL f[N][];

 int a[][N];

 inline LL sum(int x, int l, int r)

 {

     if (l>r) swap(l,r);

     LL ret=;

     for (int i=l; i<=r; i++) ret+=a[i][x];

     return ret;

 }

 int main()

 {

     int n=ra();

     for (int i=; i<; i++)

         for (int j=; j<=n; j++)

             a[i][j]=ra();

     for (int i=; i<=n; i++)

         for (int j=; j<; j++)

             f[i][j]=-INF;

     f[][]=;

     for (int i=; i<=n; i++)

     {

         for (int j=; j<; j++)

             for (int k=; k<; k++)

                 f[i][j]=max(f[i][j],f[i-][k]+sum(i,j,k));

         f[i][]=max(f[i][],f[i-][]+sum(i,,));

         f[i][]=max(f[i][],f[i-][]+sum(i,,));

         f[i][]=max(f[i][],max(f[i-][],f[i-][])+sum(i,,));

     }

     cout<<f[n][];

     return ;

 }