C#Basics_BarcodeGenerator

using System;

namespace _6Question
{
    class Program
    {
        static void Main(string[] args)
        {
            int number1 = int.Parse(Console.ReadLine());
            int number2 = int.Parse(Console.ReadLine());

            int digit4n1 = number1 % 10;
            int number11 = number1 / 10;

            int digit3n1 = number11 % 10;
            int number12 = number11 / 10;

            int digit2n1 = number12 % 10;
            int number13 = number12 / 10;

            int digit1n1 = number13 % 10;

            // -----------------------

            int digit4n2 = number2 % 10;
            int number21 = number2 / 10;

            int digit3n2 = number21 % 10;
            int number22 = number21 / 10;

            int digit2n2 = number22 % 10;
            int number23 = number22 / 10;

            int digit1n2 = number23 % 10;

            for (int a = digit1n1; a <= digit1n2; a++)
            {
                for (int b = digit2n1; b <= digit2n2; b++)
                {
                    for (int c = digit3n1; c <= digit3n2; c++)
                    {
                        for (int d = digit4n1; d <= digit4n2; d++)
                        {
                            if ((a % 2 != 0) && (b % 2 != 0) && (c % 2 != 0) && (d % 2 != 0))
                            {
                                Console.Write("{0}{1}{2}{3} ", a, b, c, d);
                            }
                        }

                    }

                }

            }

        }
    }
}