using System;
using System.Text.RegularExpressions;
 
namespace RegExApplication
{
   public class Program
   {
      public static void Main(string[] args)
      {
         string input = "atext[d][][ef]\nother[aa][][a]\nxxxxx[][xx][x][][xx]\nyyyyy[]";
         string pattern = "(?m).*(\\[.*\\])";
         Regex rgx = new Regex(pattern);
 
         Match match = rgx.Match(input);
 
        	while (match.Success)
        	{
            	Console.WriteLine(match.Groups[1].Value);
            	match = match.NextMatch();
        	}
      }
   }
}

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