#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i <= (n); i++)
#define rrep(i, n) for (int i = n - 1; i >= 0; i--)
#define rrep1(i, n) for (int i = n; i >= 1; i--)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define eb emplace_back
#define fi first
#define se second
#define sz(x) (int)(x).size()
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;
typedef long long int ll;

void speedUpIO() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
}

template <class T> bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <class T> bool chmin(T &a, const T &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
/*--------------------------------------------------*/
typedef pair<int, int> P;

const int INF = 1e9;
const ll LINF = 1e18;
const int MAX = 100010;

V<int> dx = {1, 0, -1, 0, 1, 1, -1, -1};
V<int> dy = {0, -1, 0, 1, 1, -1, 1, -1};

void solve() {
    int h, w;
    cin >> h >> w;
    VV<int> a(h, V<int>(w));
    rep(i, h) rep(j, w) cin >> a[i][j];
    int ans = 0;
    auto getIJ = [&](int ij) -> P {
        if (ij < h) return {ij, 0};
        ij -= h;
        if (ij < h) return {ij, w - 1};
        ij -= h;
        if (ij < w) return {0, ij};
        ij -= w;
        return {h - 1, ij};
    };
    VV<bool> done(2 * (h + w), V<bool>(2 * (h + w)));
    rep(ij1, 2 * (h + w)) rep(ij2, 2 * (h + w)) {
        auto [i1, j1] = getIJ(ij1);
        auto [i2, j2] = getIJ(ij2);
        if (done[min(ij1, ij2)][max(ij1, ij2)]) continue;
        done[min(ij1, ij2)][max(ij1, ij2)] = true;
        rep(d1, 8) {
            int cnt = 0;
            V<int> b1;
            int ni1 = i1, nj1 = j1;
            while (0 <= ni1 && ni1 < h && 0 <= nj1 && nj1 < w) {
                cnt += a[ni1][nj1];
                b1.eb(a[ni1][nj1]);
                a[ni1][nj1] = 0;
                ni1 += dx[d1];
                nj1 += dy[d1];
            }
            rep(d2, 8) {
                int cnt2 = cnt;
                V<int> b2;
                int ni2 = i2, nj2 = j2;
                while (0 <= ni2 && ni2 < h && 0 <= nj2 && nj2 < w) {
                    cnt2 += a[ni2][nj2];
                    b2.eb(a[ni2][nj2]);
                    a[ni2][nj2] = 0;
                    ni2 += dx[d2];
                    nj2 += dy[d2];
                }
                chmax(ans, cnt2);
                ni2 = i2, nj2 = j2;
                rep(k, sz(b2)) {
                    a[ni2][nj2] = b2[k];
                    ni2 += dx[d2];
                    nj2 += dy[d2];
                }
            }
            ni1 = i1, nj1 = j1;
            rep(k, sz(b1)) {
                a[ni1][nj1] = b1[k];
                ni1 += dx[d1];
                nj1 += dy[d1];
            }
        }
    }
    cout << ans << "\n";
}

int main() {
    speedUpIO();
    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
        // cout << solve() << "\n";
        // cout << (solve() ? "Yes" : "No") << "\n";
        // cout << fixed << setprecision(15) << solve() << "\n";
    }
    return 0;
}