// Om Namah Shivaya
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a, b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a, b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
refs:
edi
*/
const int MOD = 1e9 + 7;
const int N = 2e3 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
struct DSU {
vector<int> par, rankk, siz;
vector<int> mnj, mxj, sum;
DSU() {
}
DSU(int n) {
init(n);
}
void init(int n) {
par = vector<int>(n + 1);
rankk = vector<int>(n + 1);
siz = vector<int>(n + 1);
mnj = vector<int>(n + 1);
mxj = vector<int>(n + 1);
sum = vector<int>(n + 1);
rep(i, n + 1) create(i);
}
void create(int u) {
par[u] = u;
rankk[u] = 0;
siz[u] = 1;
mnj[u] = inf1;
mxj[u] = -inf1;
sum[u] = 0;
}
int find(int u) {
if (u == par[u]) return u;
else return par[u] = find(par[u]);
}
bool same(int u, int v) {
return find(u) == find(v);
}
void merge(int u, int v) {
u = find(u), v = find(v);
if (u == v) return;
if (rankk[u] == rankk[v]) rankk[u]++;
if (rankk[u] < rankk[v]) swap(u, v);
par[v] = u;
siz[u] += siz[v];
amin(mnj[u], mnj[v]);
amax(mxj[u], mxj[v]);
sum[u] += sum[v];
}
};
int w[N][N]; // w[j][i] = sum of segs that contain i, but not j (i > j)
void go(vector<int> &dp1, vector<int> &dp2, int l, int r, int lx, int rx){
if(l > r) return;
int mid = (l+r) >> 1;
int mx = -1;
int opt_mid = -1;
for(int i = lx; i <= rx; ++i){
if(i >= mid) break;
int cost = dp1[i] + w[i][mid];
if(cost > mx){
mx = cost;
opt_mid = i;
}
}
dp2[mid] = mx;
go(dp1,dp2,l,mid-1,lx,opt_mid);
go(dp1,dp2,mid+1,r,opt_mid,rx);
}
void solve(int test_case)
{
int n,m; cin >> n >> m;
int a[n+5][m+5];
memset(a,-1,sizeof a);
rep1(i,n){
rep1(j,m){
char ch; cin >> ch;
if(ch != '.'){
a[i][j] = ch-'0';
}
else{
a[i][j] = -1;
}
}
}
auto get = [&](int i, int j){
return (i-1)*m + j;
};
DSU dsu(n*m+5);
vector<pll> dir = {{0,1},{1,0}};
rep1(i,n){
rep1(j,m){
int ind = get(i,j);
dsu.mnj[ind] = dsu.mxj[ind] = j;
dsu.sum[ind] = a[i][j];
}
}
rep1(i,n){
rep1(j,m){
if(a[i][j] == -1) conts;
for(auto [dx,dy] : dir){
int i2 = i + dx;
int j2 = j + dy;
if(a[i2][j2] != -1){
dsu.merge(get(i,j), get(i2,j2));
}
}
}
}
vector<int> enter[m+5];
vector<pii> leave[m+5];
rep1(i,n){
rep1(j,m){
if(a[i][j] == -1) conts;
int ind = get(i,j);
if(dsu.find(ind) == ind){
int l = dsu.mnj[ind];
int r = dsu.mxj[ind];
int w = dsu.sum[ind];
enter[l].pb(w);
leave[r+1].pb({l,w});
// vector<int> t = {l,r,w};
// debug(t);
}
}
}
vector<int> sum_here(m+5);
rep1(i,m){
trav(w,enter[i]){
sum_here[i-1] += w;
}
for(auto [l,w] : leave[i]){
sum_here[l-1] -= w;
}
vector<ll> suff(m+5);
rev(j,i,0) suff[j] += suff[j+1] + sum_here[j];
rep(j,i+1){
w[j][i] = suff[j];
}
}
vector<int> dp1(m+5,-inf1);
dp1[0] = 0;
rep1(j,m){
vector<int> dp2(m+5,-inf1);
go(dp1,dp2,1,m,0,m);
dp1 = dp2;
int ans = *max_element(all(dp2));
cout << ans << endl;
}
// rep1(j,m){
// rep1(i,m){
// rep(k,i){
// amax(dp2[i], w[k][i] + dp1[k]);
// }
// }
// dp1 = dp2;
// int ans = *max_element(all(dp2));
// cout << ans << endl;
// }
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
