CountingRooms.java

import java.util.*;
import java.io.*;

class CountingRooms {
    public static void random(char[][] c, int i, int j, boolean[][] visited) {
        int n = c.length;
        int m = c[0].length;
        if(i < 0 || j < 0 || i > n-1 || j > m-1 || c[i][j] == '#' || visited[i][j]) return;
        visited[i][j] = true;
        random(c, i-1, j, visited);
        random(c, i, j+1, visited);
        random(c, i+1, j, visited);
        random(c, i, j-1, visited);
    }
	public static void main(String[] args) throws IOException
	{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String s[] = br.readLine().split(" ");
		int n = Integer.parseInt(s[0]);
		int m = Integer.parseInt(s[1]);
		char c[][] = new char[n][m];
		for(int i = 0; i < n; i++) {
		    c[i] = br.readLine().toCharArray();
		}
		int ans = 0;
		boolean[][] visited = new boolean[n][m];
		for(int i = 0; i < n; i++) {
		    for(int j = 0; j < m; j++) {
		        if(!visited[i][j] && c[i][j] == '.') {
		            ans++;
		            random(c, i, j, visited);
		        }
		    }
		}
		System.out.println(ans);
	}
}