using System;

namespace ConsoleApp19
{
    class Program
    {
        struct Students
        {
            public string Name;
            public int[] Exams;
            public double ExamMedium;

            public Students(string Name)
            {
                this.Name = Name;
                Exams = new int[5];
                ExamMedium = 0;
            }

        }

        static void ExamsMedium(ref Students[,] sd)
        {
            for (int i = 0; i < 3; i++)
            {
                for (int j = 0; j < 5; j++)
                {
                    for (int k = 0; k < 5; k++)
                        sd[i, 0].ExamMedium += Convert.ToDouble(sd[i, j].Exams[k]);
                }
                sd[i, 0].ExamMedium /= 5;
                for (int j = 0; j < 5; j++)
                    sd[i, j].ExamMedium = sd[i, 0].ExamMedium;
            }
        }

        static void StudentsWrite(Students[,] sd)
        {
            int[] arr = new int[3] { 0, 1, 2 };

            for (int i = 0; i < 3 - 1; i++)
            {
                for (int j = 0; j < 3 - i - 1; j++)
                {
                    if (sd[j, 0].ExamMedium > sd[j + 1, 0].ExamMedium)
                    {
                        // меняем элементы местами
                        int temp = arr[j];
                        arr[j] = arr[j + 1];
                        arr[j + 1] = temp;
                    }
                }
            }

            for (int i = 0; i < 3; i++)
            {
                int q = arr[i];
                Console.WriteLine("{0}я группа со средним баллом {1}", i + 1, sd[q, 0].ExamMedium);
                for (int j = 0; j < 5; j++)
                {
                    Console.Write("   {0}, оценки:", sd[q, j].Name);
                    for (int k = 0; k < 5; k++)
                    {
                        Console.Write(" {0}", sd[q, j].Exams[k]);
                    }
                    Console.WriteLine();
                }
                Console.WriteLine();
            }
        }

        static void Main(string[] args)
        {
            Students[,] students = new Students[3, 5];

            string[,] names = new string[3, 5] { { "Петров", "Иванов", "Сидоров", "Лапенко", "Ребров" },
                                                { "Римин", "Легков", "Капица", "Смирнов", "Савенко" },
                                                { "Лазарев", "Спивак", "Юдин", "Батейко", "Рыбаков" } };

            for (int i = 0; i < 3; i++)
                for (int j = 0; j < 5; j++)
                {
                    students[i, j].Name = names[i, j];
                    Random rand = new Random();
                    students[i, j].Exams = new int[] { rand.Next(2, 5), rand.Next(2, 5), rand.Next(2, 5), rand.Next(2, 5), rand.Next(2, 5) };
                }

            ExamsMedium(ref students);
            StudentsWrite(students);
            Console.ReadKey();
        }
    }
}