#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
int n, m;
char grid[2001][2001];
bool visited[2001][2001];
int dx[4]{1, -1, 0, 0}, dy[4]{0, 0, 1, -1};
int dp[2001], segtree[8001], lazy[8001];
bool inside(int x, int y) {
return x && y && x <= n && y <= m && !visited[x][y] && grid[x][y] != '.';
}
tuple<int, int, int> get_oil(int x, int y) {
tuple<int, int, int> ret = {y, y, grid[x][y] - '0'};
visited[x][y] = true;
for (int i = 0; i < 4; i++) if (inside(x + dx[i], y + dy[i])) {
tuple<int, int, int> pot = get_oil(x + dx[i], y + dy[i]);
get<0>(ret) = min(get<0>(ret), get<0>(pot));
get<1>(ret) = max(get<1>(ret), get<1>(pot));
get<2>(ret) += get<2>(pot);
}
return ret;
}
void push_lazy(int node, int l, int r) {
segtree[node] += lazy[node];
if (l != r) {
lazy[node * 2] += lazy[node];
lazy[node * 2 + 1] += lazy[node];
}
lazy[node] = 0;
}
void build(int node = 1, int l = 0, int r = m) {
lazy[node] = 0;
if (l == r) segtree[node] = dp[l];
else {
int mid = (l + r) / 2;
build(node * 2, l, mid);
build(node * 2 + 1, mid + 1, r);
segtree[node] = max(segtree[node * 2], segtree[node * 2 + 1]);
}
}
int query(int pos, int node = 1, int l = 0, int r = m) {
push_lazy(node, l, r);
if (l > pos) return 0;
if (r <= pos) return segtree[node];
int mid = (l + r) / 2;
return max(query(pos, node * 2, l, mid), query(pos, node * 2 + 1, mid + 1, r));
}
void update(int pos, int val, int node = 1, int l = 0, int r = m) {
push_lazy(node, l, r);
if (l > pos) return;
if (r <= pos) {
lazy[node] = val;
push_lazy(node, l, r);
} else {
int mid = (l + r) / 2;
update(pos, val, node * 2, l, mid);
update(pos, val, node * 2 + 1, mid + 1, r);
segtree[node] = max(segtree[node * 2], segtree[node * 2 + 1]);
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
cin >> grid[i][j];
}
vector<tuple<int, int, int>> oil;
for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
if (inside(i, j)) {
int l, r, val;
tie(l, r, val) = get_oil(i, j);
oil.push_back({l, l, val});
oil.push_back({r + 1, l, -val});
}
}
sort(oil.begin(), oil.end());
for (int _ = 1; _ <= m; _++) {
for (int i = 1, ptr = 0; i <= m; i++) {
while (get<0>(oil[ptr]) <= i) {
update(get<1>(oil[ptr]) - 1, get<2>(oil[ptr]));
ptr++;
}
dp[i] = query(i - 1);
}
build();
cout << query(m) << '\n';
}
return 0;
}
