#include <cassert>
#include <cctype>
#include <cfloat>
#include <climits>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <cfenv>
#include <cinttypes>
#include <cstdint>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <chrono>
#include <forward_list>
#include <initializer_list>
#include <random>
#include <ratio>
#include <regex>
#include <system_error>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <shared_mutex>
using namespace std;
using ll = long long;
//ライブラリを貼るところ




//ここまで

const vector<int> dx = {1, 0, -1, 0};
const vector<int> dy = {0, 1, 0, -1};

void solve(){
    int H, W; cin >> H >> W;
    vector<string> G(H);
    for(int i = 0; i < H; ++i) cin >> G[i];
    vector<vector<int>> re(H, vector<int>(W, 0));
    for(int i = 0; i < H; ++i) for(int j = 0; j < W; ++j){
        if(re[i][j] == 1) continue;
        char c = G[i][j];
        queue<pair<int, int>> q;
        q.push(make_pair(i, j));
        re[i][j] = 1;
        vector<pair<int, int>> v;
        v.emplace_back(make_pair(i, j));
        while(!q.empty()){
            auto [x, y] = q.front();
            q.pop();
            for(int k = 0; k < 4; ++k){
                if(x + dx[k] >= 0 && x + dx[k] < H && y + dy[k] >= 0 && y + dy[k] < W){
                    if(G[x + dx[k]][y + dy[k]] == c && re[x + dx[k]][y + dy[k]] == 0){
                        re[x + dx[k]][y + dy[k]] = 1;
                        q.push(make_pair(x + dx[k], y + dy[k]));
                        v.emplace_back(make_pair(x + dx[k], y + dy[k]));
                    }
                }
            }
        }
        if(v.size() >= 4){
            for(auto [x, y]: v) G[x][y] = '.';
        }
    }
    for(int i = 0; i < H; ++i) cout << G[i] << "\n";
}



int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << setprecision(16) << fixed;

    int T = 1;
    for(int i = 0; i < T; ++i) solve();
}