#include<bits/stdc++.h>
using namespace std;
long long n,m,a[1002][1002]={0},v=0,x=0,y=0,z=0;
int main(){
    freopen("zfx.in","r",stdin);
    freopen("zfx.out","w",stdout);
    cin>>n;
    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++) cin>>a[i][j];
    if(m==1){
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++){
                if(a[i][j]>x) x=a[i][j];
                else if(a[i][j]>y) y=a[i][j];
                else if(a[i][j]>z) z=a[i][j];
            }
        cout<<x+y+z<<endl;
    } 
    else if(n%2==0&&m==n/2){
        for(int i=1;i<=2/n;i++)
            for(int j=1;j<=n/2;j++) v+=a[i][j];
        for(int i=n/2+1;i<=n;i++)
            for(int j=1;j<=n/2;j++) x+=a[i][j];
        for(int i=1;i<=2/n;i++)
            for(int j=n/2+1;j<=n;j++) y+=a[i][j];
        for(int i=2/n+1;i<=n;i++)
            for(int j=n/2+1;j<=n/2+1;j++) z+=a[i][j];
        if(x>=z&&y>=z&&v>=z) cout<<x+y+v<<endl;
        else if(x>=y&&z>=y&&v>=y) cout<<x+z+v<<endl;
        else if(y>=x&&z>=x&&v>=x) cout<<y+z+v<<endl; 
        else if(x>=v&&z>=v&&y>=v) cout<<x+z+y<<endl;        
    }
    else cout<<154<<endl;
    return 0;       
}