#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define ll long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"
const int MOD = 1e9+7;
const int inf = 1e9;
const ll linf = 1e18;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
// -------------------------------------------------- Main Code --------------------------------------------------
const int N = 2005;
char arr[N][N];
int n, m, Cost[N][N], dp[N][N];
set<int> temp;
int dfs(int i, int j) {
temp.insert(j);
int cost = arr[i][j]-'0';
arr[i][j] = '.';
for (int x = 0; x < 4; x++) {
int ni = d4i[x]+i, nj = d4j[x]+j;
if (ni >= 1 && ni <= n && nj >= 1 && nj <= m && arr[ni][nj] != '.') {
cost += dfs(ni, nj);
}
}
return cost;
}
void sol() {
cin >> n >> m;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
cin >> arr[i][j];
}
}
vii cost1(m+1, vi(m+1));
for (int j = 1; j <= m; j++) {
for (int i = 1; i <= n; i++) {
if (arr[i][j] == '.') continue;
temp.clear();
int cost = dfs(i, j);
for (auto &x : temp) {
// starting from j, x.s is a part of it
cost1[j][x] += cost;
}
}
}
for (int i = 1; i <= m; i++) for (int j = 1; j <= m; j++) cost1[i][j] += cost1[i-1][j];
for (int i = 0; i <= m; i++) for (int j = 0; j <= m; j++) Cost[i][j] = cost1[j][j] - cost1[i][j];
for (int k = 1; k <= m; k++) {
for (int i = 0; i <= m; i++) {
for (int j = i; j >= 0; j--) {
// current drill on i, last drill on j
dp[i][k] = max(dp[i][k], dp[j][k-1] + Cost[j][i]);
}
}
int ans = 0;
for (int i = 0; i <= m; i++) ans = max(ans, dp[i][k]);
cout << ans << endl;
}
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
