#include<iostream>
using namespace std;
const int N = 210;
long long a[N][N], sum[N][N], ans = -2e18;
int main(){
    freopen("ring.in","r",stdin);
    freopen("ring.out","w",stdout);
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; i ++){
        for(int j = 1; j <= m; j ++){
            cin >> a[i][j];
            a[n+i][j] = a[i][m+j] = a[n+i][m+j] = a[i][j];
            ans = max(ans, a[i][j]);
        }
    }   
    for (int i = 1; i <= 2*n; i++){
        for (int j = 1; j <= 2*m; j ++){
            sum[i][j] = sum[i-1][j] + a[i][j];
        }
    }
    if(ans <= 0){
        cout << ans << endl;
    }else{
        ans = -0x3f3f3f3f;
        for(int i = 1; i <= n; i ++){
            for (int j = i; j <= 2*n && j-i+1 <= n; j ++){
                for (int u = 1; u <= m; u ++){
                    long long sumt = 0;
                    for(int k = u; k <= 2*m && k - u + 1 <= m; k ++){
                        sumt += sum[j][k] - sum[i-1][k];

                        if(sumt < 0) sumt = 0;
                        ans = max(ans, sumt);
                    }
                }

            }
        }
        cout << ans << endl;
    }
    return 0;
}

#include<bits/stdc++.h>using namespace std;long long a[405][405],sum[405];int main(){freopen("ring.in","r",stdin);freopen("ring.out","w",stdout);int n,m,len,c=0;cin>>n>>m;for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){cin>>a[i][j];a[i][j+m]=a[i+n][j]=a[i+n][j+m]=a[i][j];}}for(int i=1;i<=n*2;i++){for(int j=1;j<=m*2;j++){sum[j]+=a[(i+len-2)%n+1][j];}}long long ans=-1e18;for(int r=1;r<=n*2;r++){for(int i=1;i<=m*2;i++) sum[i]=0;for (int len =1;len<=n;len++){for(int j=1;j<=m;j++) sum[j]+=a[(r + len - 2) % n + 1][j];long long cur=sum[1],mx=sum[1];for(int j=2;j<=m;j++){cur=max(sum[j],cur+sum[j]);mx=max(mx,cur);}ans=max(ans,mx);}}cout<<ans<<endl;return 0;}