using System.Text.RegularExpressions;
public static void Main()
String s = " Ddd ddd hh hhh hhh hhh. Aaa aaa aa bbbb bbbb bbb bbb bbb.";
String[] ss1 = Regex.Split(s.Trim(), @"\W+");
Console.WriteLine(i + "_");
Console.WriteLine(Regex.Replace(s, @"^\W+", ""));
Console.WriteLine(Regex.Replace(s, @"\W+$", ""));
Console.WriteLine(Regex.Replace(s, @"^\W+|\W+$", ""));
String preparedForSplit = Regex.Replace(s.Trim(), @"^\W+|\W+$", "");
String[] ss2 = Regex.Split(preparedForSplit, @"\W+");
Console.WriteLine(i + "_");