#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define ins insert
#define pq priority_queue
#define minele min_element
#define maxele max_element
#define lb lower_bound //first pos >= val
#define ub upper_bound // first pos > val
#define cnt_bit __builtin_popcount
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;


int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

const ll oo = 1e18;
const ll maxN = 1e6;

/* Author : Le Ngoc Bao Anh, 10A5, LQD High School for Gifted Student */

void maximize(int &a, int b) {
    a = max(a, b);
}

void minimize(int &a, int b) {
    a = min(a, b);
}

const int N = 5005;
struct E {
    int x, y, dist;
};
vector<E> ed;
ll dp[N][3][2], ndp[N][3][2];
int a[N];

void solve() {
    int n, m;
    cin >> n >> m;

    auto f = [&](int i, int j) -> int {
        return (i - 1) * m + j;
    };

    auto maximize = [&](ll &x, ll y) -> void {
        if(x < y) x = y;
    };

    auto minimize = [&](ll &x, ll y) -> void {
        if(x > y) x = y;
    };

    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) cin >> a[f(i, j)];
    }

    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= m; j++) {
            int r = f(i, j);
            dp[r][0][0] = dp[r][0][1] = a[r];
            dp[r][1][0] = dp[r][2][0] = -oo;
            dp[r][1][1] = dp[r][2][1] = oo;
            for(int x = 0; x < 3; x++) {
                for(int y = 0; y < 2; y++) ndp[r][x][y] = dp[r][x][y];
            }

            if(i == 1 && j == 1) continue;
            int dist = (i - 1) * (i - 1) + (j - 1) * (j - 1);
            ed.pb({i - 1, j - 1, dist});
        }
    }

    sort(ed.begin(), ed.end(), [&](E _a, E _b) {
        return _a.dist < _b.dist;
    });

    int ed_num = ed.size(); ll ans = 0;
    for(int c = 0; c < ed_num; c++) {
        int x = ed[c].x, y = ed[c].y;
        for(int i = 1; i <= n; i++) {
            for(int j = 1; j <= m; j++) {
                int r = f(i, j);
                for(int ii = 0; ii < 2; ii++) {
                    for(int jj = 0; jj < 2; jj++) {
                        int fx = i + (ii ? x : -x);
                        int fy = j + (jj ? y : -y);
                        if(fx > 0 && fy > 0 && fx <= n && fy <= m) {
                            int b = f(fx, fy);
                            maximize(ndp[b][1][0], dp[r][0][0] + a[b]);
                            maximize(ndp[b][2][0], dp[r][1][0] + a[b]);
                            maximize(ndp[b][2][0], dp[r][2][0] + a[b]);
                            minimize(ndp[b][1][1], dp[r][0][1] + a[b]);
                            minimize(ndp[b][2][1], dp[r][1][1] + a[b]);
                            minimize(ndp[b][2][1], dp[r][2][1] + a[b]);
                        }
                    }
                }
            }
        }

        if(c < ed_num - 1 && ed[c].dist < ed[c + 1].dist) {
            for(int i = 1; i <= n * m; i++) {
                for(int x = 0; x < 3; x++) {
                    for(int y = 0; y < 2; y++) {
                        dp[i][x][y] = ndp[i][x][y];
                    }
                }
            }
        }
    }

    for(int i = 1; i <= n * m; i++) {
        maximize(ans, ndp[i][2][0]);
        maximize(ans, -ndp[i][2][1]);
    }
    cout << ans;
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #else
    //online
    #endif

    int tc = 1, ddd = 0;
    // cin >> tc;
    while(tc--) {
        //ddd++;
        //cout << "Case #" << ddd << ": ";
        solve();
    }
}