// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#ifdef ULVI
#include "debug.hpp"
#else
#define db(...)
#define dbv(v)
#define line()
#endif
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define ff first
#define ss second
#define enld endl
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<ll,ll> pll;
const ll sz=2e5+100;
const ll lg=20;
const ll mod=1e9+7;
const ll inf=1e18;
template<class T>
using indexed_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll f(ll n,ll m,vector<vector<ll>> v){
array<ll,3> tmpmn={inf,inf,inf};
array<ll,3> tmpmx={-inf,-inf,-inf};
vector<vector<array<ll,3>>> prefmn(n+5,vector<array<ll,3>>(m+5,tmpmn));
vector<vector<array<ll,3>>> prefmx(n+5,vector<array<ll,3>>(m+5,tmpmx));
for(ll i=1;i<=n;i++){
for(ll j=1;j<=m;j++){
prefmn[i][j]=min({prefmn[i-1][j],prefmn[i][j-1],{v[i][j]-i-j,i,j}});
prefmx[i][j]=max({prefmx[i-1][j],prefmx[i][j-1],{v[i][j]+i+j,i,j}});
}
}
ll ans=-1;
for(ll i=1;i<=n;i++){
for(ll j=1;j<=m;j++){
auto mn=min(prefmn[i-1][j],prefmn[i][j-1]);
auto mx=max(prefmx[i-1][j],prefmx[i][j-1]);
ll o=v[i][j]-(mn[0]+mn[1]+mn[2])-(i+j-mn[1]-mn[2]+1);
ll p=(mx[0]-mx[1]-mx[2])-v[i][j]-(i+j-mx[1]-mx[2]+1);
ans=max({ans,o,p});
}
}
return ans;
}
void solve(){
ll n,m;
cin>>n>>m;
vector<vector<ll>> v(n+1,vector<ll>(m+1));
for(ll i=1;i<=n;i++){
for(ll j=1;j<=m;j++) cin>>v[i][j];
}
ll ans=f(n,m,v);
for(ll i=1;i<=n;i++) reverse(v[i].begin()+1,v[i].end());
ans=max(ans,f(n,m,v));
cout<<ans<<'\n';
}
int main(){
// freopen("input.txt","r",stdin);
// freopen("output.txt","w",stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
ll t=1;
// cin>>t;
for(ll _=1;_<=t;_++){
// cout<<"Scenario #"<<_<<":\n";
solve();
}
}
