static void Main(string[] args)
{
Console.WriteLine("Hej");
GradeBook book1 = new GradeBook();
book1.AddGrade(22f);
List <float> allGrades = book1.getAllGrades();
Console.WriteLine(allGrades.First());
GradeStatistics stats = book1.ComputeGradeStatistics();
WriteResult("Average", stats.AverageGrade);
}