RegEx Lab - 03. Match Hexadecimal Numbers

using System;
using System.Linq;
using System.Text.RegularExpressions;

namespace _10a_Regular_Expressions_RegEx_Lab
{
    class Regular_Expressions_RegEx_Lab
    {
       static void Main(string[] args)
        {
            string input = Console.ReadLine();
            Regex reg = new Regex(@"\b[0x]*?[0-9A-F]+\b");
            var matches = reg.Matches(input).Cast<Match>().Select(m => m.Value).ToArray();
            //Thiw below is working only in ".NET Core"!?
            //MatchCollection matches = reg.Matches(input);
            Console.WriteLine(string.Join(" ", matches));
        }
    }
}