// 01001100 01001111 01010100 01000001 \\
// \\
// ╦ ╔═╗╔╦╗╔═╗ \\
// ║ ║ ║ ║ ╠═╣ \\
// ╩═╝╚═╝ ╩ ╩ ╩ \\
// \\
// 01001100 01001111 01010100 01000001 \\
#include <bits/stdc++.h>
using namespace std;
#define nl '\n'
#define ff first
#define ss second
#define ll long long
#define ld long double
#define terminator main
#define pll pair<ll,ll>
#define add insert
#define append push_back
#define pii pair<int,int>
#define all(x) (x).begin(),(x).end()
#define L0TA ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
const int N = 1e3 + 3;
int a[N][N];
int x[N][N][4];
void solve(){
int n, m, ans;
cin >> n >> m;
for(int i = 1; i <= n; i++)
for(int j = 1; j <= m; j++)
cin >> a[i][j];
for(int i = 0; i < n + 2; i++)
for(int j = 0; j < m + 2; j++)
for(int k = 0; k < 4; k++)
x[i][j][k] = -1e9;
for(int i = 1; i <= n; i++)
for(int j = 1; j <= m; j++)
x[i][j][0] = max(max(x[i - 1][j][0], x[i][j - 1][0]), - a[i][j] + i + j);
for(int i = 1; i <= n; i++)
for(int j = m; j > 0; j--)
x[i][j][1] = max(max(x[i - 1][j][1], x[i][j + 1][1]), - a[i][j] + i - j);
for(int i = n; i > 0; i--)
for(int j = 1; j <= m; j++)
x[i][j][2] = max(max(x[i + 1][j][2], x[i][j - 1][2]), - a[i][j] - i + j);
for(int i = n; i > 0; i--)
for(int j = m; j > 0; j--)
x[i][j][3] = max(max(x[i + 1][j][3], x[i][j + 1][3]), - a[i][j] - i - j);
ans = -1e9;
for(int i = 1; i <= n; i++){
for(int j = 1; j <= m; j++){
ans = max(ans, a[i][j] - i - j + x[i][j][0] - 1);
ans = max(ans, a[i][j] - i + j + x[i][j][1] - 1);
ans = max(ans, a[i][j] + i - j + x[i][j][2] - 1);
ans = max(ans, a[i][j] + i + j + x[i][j][3] - 1);
}
}
cout << ans;
}
int terminator(){
L0TA;
int T = 1;
//cin >> T;
while(T--)
solve();
return 0;
}
