/* -*- coding: utf-8 -*-
 *
 * 2509.cc:  No.2509 Beam Shateki - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_H = 100;
const int MAX_W = 100;

/* typedef */

/* global variables */

int as[MAX_H][MAX_W];
int hs[MAX_H], vs[MAX_W], ps[MAX_H + MAX_W], qs[MAX_H + MAX_W];

/* subroutines */

/* main */

int main() {
  int h, w;
  scanf("%d%d", &h, &w);

  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++) {
      scanf("%d", as[i] + j);
      hs[i] += as[i][j];
      vs[j] += as[i][j];
      ps[i + j] += as[i][j];
      qs[i + (w - 1 - j)] += as[i][j];
    }

  int maxs = 0;
  for (int i = 0; i < h; i++)
    for (int j = 0; j < w; j++) {
      int ds[4] = { hs[i], vs[j], ps[i + j], qs[i + (w - 1 - j)] };
      sort(ds, ds + 4);
      int s = ds[3] + ds[2] - as[i][j];
      maxs = max(maxs ,s );
    }

  for (int i = 0; i < h; i++)
    for (int j = i + 1; j < h; j++)
      maxs = max(maxs, hs[i] + hs[j]);
  for (int i = 0; i < w; i++)
    for (int j = i + 1; j < w; j++)
      maxs = max(maxs, vs[i] + vs[j]);

  int hw = h + w - 1;
  for (int i = 0; i < hw; i++)
    for (int j = i + 1; j < hw; j++)
      maxs = max(maxs, max(ps[i] + ps[j], qs[i] + qs[j]));
  
  printf("%d\n", maxs);

  return 0;
}