#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define fs first
#define sc second
#define tlll tuple<ll,ll,ll>
const int inf = 1e9;
const int mxn = 1010;
int arr[mxn][mxn];
int dp[mxn][mxn];
int N,M;
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N>>M;
for(auto &i:arr)for(auto &j:i)j = -inf*2;
for(auto &i:dp)for(auto &j:i)j = -inf*2;
for(int i = 1;i<=N;i++){
for(int j = 1;j<=M;j++)cin>>arr[i][j];
}
int ans = -inf*2;
for(int i = 1;i<=N;i++){
for(int j = 1;j<=M;j++){
dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
dp[i][j] = max(dp[i][j],-arr[i][j]+i+j);
ans = max(ans,dp[i][j]-i-j+arr[i][j]-1);
}
}
for(int i = N;i>=1;i--){
for(int j = 1;j<=M;j++){
dp[i][j] = max(dp[i+1][j],dp[i][j-1]);
dp[i][j] = max(dp[i][j],-arr[i][j]-i+j);
ans = max(ans,dp[i][j]+i-j+arr[i][j]-1);
}
}
for(int i = 1;i<=N;i++){
for(int j = M;j>=1;j--){
dp[i][j] = max(dp[i-1][j],dp[i][j+1]);
dp[i][j] = max(dp[i][j],-arr[i][j]+i-j);
ans = max(ans,dp[i][j]-i+j+arr[i][j]-1);
}
}
for(int i = N;i>=1;i--){
for(int j = M;j>=1;j--){
dp[i][j] = max(dp[i+1][j],dp[i][j+1]);
dp[i][j] = max(dp[i][j],-arr[i][j]-i-j);
ans = max(ans,dp[i][j]+i+j+arr[i][j]-1);
}
}
cout<<ans<<'\n';
return 0;
}
