static void Main(string[] args)
{
Diary student1 = new Diary();
student1.AddName();
Diary.AskForRatings(student1);
DiaryStatistic stats = student1.ComputeStatistic();
DiaryStatistic.ShowStatistic(stats);
Diary student2 = new Diary();
student2.AddName();
Diary.AskForRatings(student2);
stats = student2.ComputeStatistic();
DiaryStatistic.ShowStatistic(stats);
}