#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
const ll ILL=2167167167167167167;
const int INF=2100000000;
const int mod=998244353;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}
template<class T> void vec_out(vector<T> &p,int ty=0){
if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){assert(!a.empty());T ans=a[0]-a[0];for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}



void solve();
// oddloop
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int t=1;
    //cin>>t;
    rep(i,0,t) solve();
}

void solve(){
    int H,W;
    cin>>H>>W;
    vector<vector<int>> A(H,vector<int>(W));
    rep(i,0,H) rep(j,0,W) cin>>A[i][j];
    vector<pair<int,int>> st;
    rep(i,0,H) st.push_back({i,-1});
    rep(i,0,H) st.push_back({i,W});
    rep(i,-1,W+1) st.push_back({-1,i});
    rep(i,-1,W+1) st.push_back({H,i});
    vector<vector<pair<int,int>>> op;
    vector<int> dx={1,1,1,0,0,-1,-1,-1},dy={-1,0,1,1,-1,0,1,-1};
    for(auto s:st){
        int x,y;
        vector<pair<int,int>> tmp;
        rep(k,0,8){
            tie(x,y)=s;
            while(true){
                x+=dx[k],y+=dy[k];
                if(x<0||H<=x||y<0||W<=y) break;
                //if(op.empty()) cout<<x<<" "<<y<<endl;
                tmp.push_back({x,y});
            }
            if(!tmp.empty()) op.push_back(tmp);
            tmp.clear();
        }
    }
    int ans=0;
    vector<vector<int>> B(H,vector<int>(W,-1));
    int val=0;
    rep(i,0,op.size()) rep(j,i+1,op.size()){
        vector<int> q={i,j};
        int tmp=0;
        rep(k,0,2)for(auto x:op[q[k]]){
            int a,b;
            tie(a,b)=x;
            //cout<<" "<<k<<" "<<a<<" "<<b<<endl;
            if(B[a][b]!=val) tmp+=A[a][b],B[a][b]=val;
        }
        val++;
        chmax(ans,tmp);
        //cout<<tmp<<endl;
    }
    cout<<ans<<"\n";
}