#include <bits/stdc++.h>
using namespace std;

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

int main() {
	fast_io();
	int h, w;
	cin >> h >> w;
	vector<string> g(h);
	for (int i = 0; i < h; i++) {
		cin >> g[i];
	}
	int dx[] = {0, 0, 1, -1};
	int dy[] = {1, -1, 0, 0};
	auto is_in = [&](int x, int y) {
		return 0 <= x && x < h && 0 <= y && y < w;
	};
	vector<vector<bool>> vis(h, vector<bool>(w));
	vector<string> ans = g;
	for (int i = 0; i < h; i++) {
		for (int j = 0; j < w; j++) {
			if (vis[i][j]) {
				continue;
			}
			deque<pair<int, int>> dq{{i, j}};
			vector<pair<int, int>> v{{i, j}};
			vis[i][j] = true;
			while (!dq.empty()) {
				auto [x, y] = dq.front();
				dq.pop_front();
				for (int k = 0; k < 4; k++) {
					int nx = x + dx[k];
					int ny = y + dy[k];
					if (is_in(nx, ny) && !vis[nx][ny] && g[nx][ny] == g[x][y]) {
						vis[nx][ny] = true;
						dq.push_back({nx, ny});
						v.push_back({nx, ny});
					}
				}
			}
			if (v.size() >= 4) {
				for (auto [x, y] : v) {
					ans[x][y] = '.';
				}
			}
		}
	}
	for (int i = 0; i < h; i++) {
		cout << ans[i] << "\n";
	}
}