#include <bits/stdc++.h>
using namespace std;
#define sz(x) int(x.size())
#define all(x) begin(x),end(x)
const int INF = 2e9;
int solve(vector<vector<int>> &a) {
int n = sz(a), m = sz(a[0]);
vector<vector<int>> dp(n, vector<int>(m));
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
dp[i][j] = -a[i][j] + i + j - 1;
if (i != 0) dp[i][j] = max(dp[i][j], dp[i - 1][j]);
if (j != 0) dp[i][j] = max(dp[i][j], dp[i][j - 1]);
}
}
int ans = -INF;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
ans = max(ans, a[i][j] - i - j + dp[i][j]);
}
}
return ans;
}
vector<vector<int>> transpose(vector<vector<int>> &a) {
int n = sz(a), m = sz(a[0]);
vector<vector<int>> t(m, vector<int>(n));
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
t[j][i] = a[i][j];
}
}
return t;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m;
cin >> n >> m;
vector<vector<int>> a(n, vector<int>(m));
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
cin >> a[i][j];
}
}
int ans = -INF;
int r = 4;
while (r--) {
a = transpose(a), swap(n, m);
for (int i = 0; i < n; i++) {
reverse(all(a[i]));
}
ans = max(ans, solve(a));
}
cout << ans << '\n';
return 0;
}
