using System;

using System.Linq;

using System.Text.RegularExpressions;

public class Program

{

    public int? _x = null;

    private static Regex slackSubRegex = new Regex(@"^oauth2\|slack|(T.+)-(U.+)$", RegexOptions.Compiled);

​

    public static void Main()

    {

        var match = slackSubRegex.Match("oauth2|slack|T0xxxxxxxxx-U0xxxxxxxxx");

        Console.WriteLine(match.Captures.Count);

        Console.WriteLine(match.Groups[1]);

    }

}