/*#pragma GCC optimize("O3")
#pragma GCC target ("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")*/
#include <bits/stdc++.h>
#pragma GCC optimize ("unroll-loops,Ofast,O3")
#pragma GCC target("avx,avx2,fma")
//#define file(data) freopen(data".in", "r", stdin); freopen(data".out", "w", stdout);
#define pb push_back
//#define ios ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define all(data) data.begin() , data.end()
#define endl '\n'
//freopen("nenokku_easy.in", "r", stdin);
//freopen("nenokku_easy.out", "w", stdout);
#define int long long
#define pii pair < int, int >
#define pll pair < long long, long long >
using namespace std;
typedef long long ll;
const int N = 1e3 + 5;
const int M = 305;
const int mod = 1e9 + 7;
int n, m, a[N][N], uppref[N][N], downpref[N][N], upsuff[N][N], downsuff[N][N];
void calc() {
for(int i = 0; i <= n + 1; i++) {
for(int j = 0; j <= m + 1; j++) {
uppref[i][j] = upsuff[i][j] = downpref[i][j] = downsuff[i][j] = -1e10;
}
}
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
uppref[i][j] = max(max(uppref[i - 1][j], uppref[i][j - 1]), (-a[i][j] + i + j));
}
}
for(int i = 1; i <= n; i++) {
for(int j = m; j > 0; j--) {
upsuff[i][j] = max(max(upsuff[i - 1][j], upsuff[i][j + 1]), (-a[i][j] + i - j));
}
}
for(int i = n; i > 0; i--) {
for(int j = 1; j <= m; j++) {
downpref[i][j] = max(max(downpref[i + 1][j], downpref[i][j - 1]), (-a[i][j] - i + j));
}
}
for(int i = n; i > 0; i--) {
for(int j = m; j > 0; j--) {
downsuff[i][j] = max(max(downsuff[i + 1][j], downsuff[i][j + 1]), (-a[i][j] - i - j));
}
}
}
int get(int i, int j) {
int res = a[i][j] - i - j + max(uppref[i - 1][j], uppref[i][j - 1]);
res = max(res, a[i][j] - i + j + max(upsuff[i - 1][j], upsuff[i][j + 1]));
res = max(res, a[i][j] + i - j + max(downpref[i][j - 1], downpref[i + 1][j]));
res = max(res, a[i][j] + i + j + max(downsuff[i + 1][j], downsuff[i][j + 1]));
return res - 1;
}
main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
//file("pieaters");
cin >> n >> m;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
cin >> a[i][j];
}
}
calc();
int ans = -1;
for(int i = 1; i <= n; i++) {
for(int j = 1; j <= m; j++) {
ans = max(ans, get(i, j));
//cout << get(i, j) << " ";
//cout << uppref[i][j] << " ";
}
//cout << endl;
}
cout << ans;
}
