using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var subjectString = "hello:123.11,good:456,bye:789.78";

        var result = Regex.Matches(subjectString, @"[-+]?(\d*[.])?\d+");

        foreach(var item in result)

        {

            Console.WriteLine(item);

        }

    }

}