using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var strs = new List<string> { "abc", "ab .c", "ab123,cd2,  ,,%&$§56"};
        foreach (var input in strs) {
        	var output = Regex.Matches(input, @"[\p{L}\p{N}]+").Cast<Match>().Select(x => x.Value);
        	Console.WriteLine($"--- Checking {input} ---");
        	Console.WriteLine(string.Join("; ", output));
        }
	}
}

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