#include <iostream>

using namespace std;

int i, n, j, mat[51][51], mx = -101, s;
struct colt {
    int lin, col;
};

colt a, b, c, d;// v, l, k, m;

int main() {
    cin >> n;

    for(i = 1;i <= n;i++)
    for(j = 1;j <= n;j++) {
        cin >> mat[i][j];
    }

    a.lin = a.col = b.lin = b.col = c.lin = c.col = d.lin = d.col = 1;

    while(a.lin <= n) {
        s = 0;

        i = a.lin;
        j = a.col;

        while(j <= b.col) {
            s += mat[i][j];
            j++;
        }

        j--;
        i++;

        while(i <= c.lin) {
            s += mat[i][j];
            i++;
        }

        i--;
        j--;

        while(j >= d.col) {
            s += mat[i][j];
            j--;
        }

        j++;
        i--;

        while(i > a.lin) {
            s += mat[i][j];
            i--;
        }

        if(s > mx) {
           /* v = a;
            l = b;
            k = c;
            m = d;*/
            mx = s;
        }

        b.col++;
        c.lin++;
        c.col++;
        d.lin++;
        if(b.col > n || d.lin > n || c.lin > n || c.col > n) {
            a.col++;
            if(a.col > n) {
                a.lin++;
                a.col = 1;
            }
            b.col = c.col = d.col = a.col;
            b.lin = c.lin = d.lin = a.lin;
        }
    }

    cout << mx << '\n';

    return 0;
}