for each '.' cell we have to made dfs(or bfs) and keep on coloring the visited nodes.we keep track number of dfs by count variable .our answer would be count.

   fo(i,0,n){
   	string s;
   	cin>>s;
   	fo(j,0,m){
   		if(s[j]=='.')grid[i][j]=1;
   		else grid[i][j]=0;
   	}
   }
   int ans=0;
   fo(i,0,n){
   	fo(j,0,m){
   		if(grid[i][j]==1&&vis[i][j]==-1){
   			dfs(i,j);
   			ans++;
   		}
   	}
   }
   cout<<ans<<endl;