using System;
using System.Text.RegularExpressions;

public class Test
{
	public static void Main()
	{
		string s = "protected void Page_Load(object sender, EventArgs e)\n{\n\tResponse.Write(\"Hello World\");\n}";
		Regex regex = new Regex(@"^\t+", RegexOptions.Multiline);
		s = regex.Replace(s, m => new string('*', 4 * m.Value.Length));
		Console.WriteLine(s);
	}
}