#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

int H,W;
int A[102][102];

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>H>>W;
	FOR(y,H) FOR(x,W) cin>>A[y+1][x+1];
	
	int ma=0;
	vector<pair<int,int>> V;
	FOR(y,H+2) V.push_back({y,0}),V.push_back({y,W+1});
	FOR(x,W+2) V.push_back({0,x}),V.push_back({H+1,x});
	
	FORR2(ay,ax,V) FORR2(by,bx,V) {
		int dy[]={1,1,1,0,0,-1,-1,-1};
		int dx[]={-1,0,1,-1,1,-1,0,1};
		
		FOR(i,8) FOR(j,8) {
			set<pair<int,int>> S;
			int cy=ay,cx=ax;
			while(1) {
				cy+=dy[i];
				cx+=dx[i];
				if(cy<0||cy>H+1||cx<0||cx>W+1) break;
				S.insert({cy,cx});
				
			}
			cy=by,cx=bx;
			while(1) {
				cy+=dy[j];
				cx+=dx[j];
				if(cy<0||cy>H+1||cx<0||cx>W+1) break;
				S.insert({cy,cx});
				
			}
			int sum=0;
			FORR2(y,x,S) sum+=A[y][x];
			ma=max(ma,sum);
		}
	}
	cout<<ma<<endl;
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}