public int find(String[] board)
	{
		numRows = board.length;
		numCols = board[0].length();
		if (numRows <= 1)
			return 0;
		myBoard = new boolean[numRows][numCols];
		for (int i = 0; i < numRows; i++)
			for (int j = 0; j < numCols; j++) {
				if (board[i].charAt(j) == 'X')
					myBoard[i][j] = false;
				else {
					myBoard[i][j] = true;
					if ((i + j) % 2 == 0)
						maxPossible++;
				}
			}
		dfs(0, board);
		return maxTiles;
	}