525D

#include<bits/stdc++.h>
using namespace std;
/// from HUNG MINE with love <3
int a[3001][3001], n, m;
void dfs (int x, int y) {
      if (x < 1 || y < 1 || x > n || y > m) return;
      int d = 0;
      for (int i = -1; i <= 0; ++ i) {
            for (int j = -1; j <= 0; ++ j) {
                  if (x + i < 1 || y + j < 1) return;
                  else if (a[x + i][y + j] == 0) {
                        ++ d;
                  }
            }
      }
      //cout << x << " " << y << " " << d << "\n";
      if (d != 3) return;
      for (int i = -1; i <= 0; ++ i) {
            for (int j = -1; j <= 0; ++ j) {
                  a[x + i][y + j] = 0;
            }
      }
      for (int i = -1; i <= 1; ++ i) {
            for (int j = -1; j <= 1; ++ j) {
                  dfs (x + i, y + j);
            }
      }
}
int main () {
      if (fopen ("test.inp", "r")) {
            freopen ("test.inp", "r", stdin);
      }
//      else {
//            freopen (".inp", "r", stdin);
//            freopen (".out", "w", stdout);
//      }

      ios_base :: sync_with_stdio (0);
      cin.tie (0);
      cout.tie (0);
      cin >> n >> m;
      for (int i = 1; i <= n; ++ i) {
            for (int j = 1; j <= m; ++ j) {
                  char c;
                  cin >> c;
                  a[i][j] = (c == '*');
            }
      }
      for (int i = 1; i <= n; ++ i) {
            for (int j = 1; j <= m; ++ j) {
                  dfs (i, j);
            }
      }
      for (int i = 1; i <= n; ++ i) {
            for (int j = 1; j <= m; ++ j) {
                  if (a[i][j] == 0) {
                        cout << ".";
                  }
                  else {
                        cout << "*";
                  }
            }
            cout << "\n";
      }
}