#include "bits/stdc++.h"
using namespace std;
#define int long long
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ss second
#define ff first
#define pb push_back
void solve(){
int n, m; cin >> n >> m;
vector<vector<int>> grid(n, vector<int> (m));
int x = 0, y = 0;
int mx = 0;
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
cin >> grid[i][j];
if(mx < grid[i][j]){
mx = grid[i][j];
x = i; y = j;
}
}
}
int ans = 0;
for(int i = 0; i < n; i++){
for(int j = 0; j < m; j++){
ans = max(ans, mx - grid[i][j] - ((abs(i - x) + abs(j - y) + 1)));
}
}
cout << ans;
}
signed main() {
cin.tie(nullptr)->sync_with_stdio(false);
int t = 1; //cin >> t;
while(t--){
solve();
//cout << endl;
}
return 0;
}
