using System;

public class Program

{

    public static int asciiCodeZero = 48;

    public static int asciiCodeNine = 57;

    public static int asciiCodeA = 65;

    public static int asciiCodeZ = 90;

    public static int currentASCIICode = 48;

    public static void Main()

    {

        for (int x=0; x < 36; x++)

        {

            char character = (char) currentASCIICode;

            Console.WriteLine(character);

            if (currentASCIICode == asciiCodeNine) 

            {

                currentASCIICode = asciiCodeA;

            } 

            else if (currentASCIICode == asciiCodeZ) 

            {

                currentASCIICode = asciiCodeZero;

            }

            else

            {

                currentASCIICode +=1;

            }       

​

        }

    }

}