#include<fstream>
using namespace std;
int main()
{
    int n,i,j,k,a[100][100],max=-5000,v[100],l,p,s,l1,m;
    ifstream fin("maxsquare.in");
    ofstream fout("maxsquare.out");
    fin>>n;
    for(i=1; i<=n; ++i)
        for(j=1; j<=n; ++j)
            fin>>a[i][j];
    for(i=1; i<=n; ++i)
        for(j=1; j<=n; ++j)
            for(k=1; k<=n-j+1; ++k)
            {
                p=0;
                if(k<=2)
                    for(l=1; l<=k; ++l)
                        for(s=1; s<=k; ++s)
                            p=p+a[l+i-1][s+j-1];
                else
                {
                    for(l1=i; l1<=k; ++l1)
                        p+=a[l1][j]+a[l1][j];
                    for(m=j; m<=j; ++m)
                        p+=a[i][m]+a[i][m];
                }
                if(p>max)
                    max=p;
            }
    fout<<max;
    fin.close();
    fout.close();
    return 0;
}