#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18
#define f first
#define s second
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e3 + 69;
int seg[4 * N][4];
int a[N][N];
void update(int l, int r, int pos, int qp, int v, int i){
seg[pos][i] = max(seg[pos][i], v);
if (l == r) return;
int mid = (l + r)/2;
if (qp <= mid) update(l, mid, pos*2, qp, v, i);
else update(mid + 1, r, pos*2 + 1, qp, v, i);
}
int query(int l, int r, int pos, int ql, int qr, int i){
if (l >= ql && r <= qr) return seg[pos][i];
else if (l > qr || r < ql) return -INF;
int mid = (l + r)/2;
return max(query(l, mid, pos*2, ql, qr, i), query(mid + 1, r, pos*2 + 1, ql, qr, i));
}
void Solve()
{
int n, m; 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 < 4 * N; i++){
for (int j = 0; j < 4; j++) {
seg[i][j] = -INF;
}
}
int ans = -1;
for (int i = 1; i <= n; i++){
for (int j = 1; j <= m; j++){
// 0 --> a, y -, -
// 1 --> a, y +, -
// 2 --> a, y -, +
// 3 --> a, y +, +
ans = max(ans, query(1, m, 1, j, m, 0) + a[i][j] + j - i - 1);
ans = max(ans, query(1, m, 1, j, m, 1) - a[i][j] + j - i - 1);
ans = max(ans, query(1, m, 1, 1, j, 2) + a[i][j] - j - i - 1);
ans = max(ans, query(1, m, 1, 1, j, 3) - a[i][j] - j - i - 1);
update(1, m, 1, j, -a[i][j] - j + i, 0);
update(1, m, 1, j, a[i][j] - j + i, 1);
update(1, m, 1, j, -a[i][j] + j + i, 2);
update(1, m, 1, j, a[i][j] + j + i, 3);
}
}
cout << ans << "\n";
}
int32_t main()
{
auto begin = std::chrono::high_resolution_clock::now();
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
for(int i = 1; i <= t; i++)
{
//cout << "Case #" << i << ": ";
Solve();
}
auto end = std::chrono::high_resolution_clock::now();
auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";
return 0;
}
