//# include <fstream>
 # include <iostream>
 
 # define dim 105
 
 using namespace std;
 
// ifstream f("square.in");
// ofstream g("square.out");
 
 int a[ dim ][ dim ], lin[ dim ][ dim ], col[ dim ][ dim ];
 int n;
 int sol = -999999999;
 
 void citire()
 {
	 int i, j;
	 cin >> n;
	 for ( i = 1 ; i <= n ; i++ )
		 for ( j = 1 ; j <= n ; j++ )
		 {
			 cin >> a[ i ][ j ];
			 lin[ i ][ j ] = a[ i ][ j ] + lin[ i ][ j - 1 ];
			 col[ i ][ j ] = a[ i ][ j ] + col[ i - 1 ][ j ];
		 }
		 /*
	for ( i = 1 ; i <= n ; i++ )
	{
		for ( j = 1 ; j <= n ; j++ )
		
			g << col[ i ][ j ] << " ";
		g << "\n";
	}
		 */
 }
 
 void rezolvare()
 {
	 int i, j, x, y;
	 for ( i = 1 ; i <= n ; i++ )
		 for ( j = 1 ; j <= n ; j++ )
		 {
			 x = i;
			 y = j;
			 
			 sol = max( sol, lin[ i ][ y ] + lin[ x ][ y ] + ( col[ x - 1 ][ j ] - col[ i ][ j ] ) + ( col[ x - 1 ][ y ] - col[ i ][ y ] ) );
			 
			 while ( x <= n && y <= n )
			 {
				 //sol = 0;
				 x++;
				 y++;
				 sol = max( sol, lin[ i ][ y ] + lin[ x ][ y ] + ( col[ x - 1 ][ j ] - col[ i ][ j ] ) + ( col[ x - 1 ][ y ] - col[ i ][ y ] ) ) ;
			 }
		 }
				 
 }
 
 int main()
 {
	 citire();
	 rezolvare();
	 cout << sol;
	 return 0;
 }