using System;

​

public class Program

{

    public static void Main()

    {

        string[] row = new string[]{"A", "B", "C", "D"};

        int Kelas = 1, NPM = 7;

        while (Kelas < 11)

        {

            if (Kelas == NPM)

            {

                Console.WriteLine("");

                Array.Reverse(row);

            }

            else

            {

                Console.WriteLine("Kelas" + Kelas + "." + row[0] + "\t" + "Kelas" + Kelas + "." + row[1] + "\t" + "Kelas" + Kelas + "." + row[2] + "\t" + "Kelas" + Kelas + "." + row[3]);

            }

​

            Kelas++;

        }

    }

}