using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string s = @"5.0.100-preview.8.20373.19 [C:\Program Files\dotnet\sdk]";

        Console.WriteLine((new Regex(@"^(\d+\.\d+\.\d+.*) \[(.*)\]$", RegexOptions.Multiline)).Match(s).Groups[2].Value);

        Console.WriteLine((new Regex(@"(\S+) \[(.*)]$", RegexOptions.Multiline)).Match(s).Groups[1].Value);

    }

}