Encrypted-Matrix

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication4
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            string marker = Console.ReadLine();
            List<int> numbers = new List<int>();
            List<int> convertedNumbers = new List<int>();
            List<int> finalNumbers = new List<int>();
            int counter = 0;
            foreach (var letter in input)
            {
                int number = (int)letter;
                int lastNumber = number % 10;
                numbers.Add(lastNumber);
                counter++;
            }
            //foreach (var item in numbers)
            //{
            //    Console.Write(item + " ");
            //}
            if (counter <= 1)
            {
                Console.WriteLine(numbers[0]);
            }
            else
            {
                for (int i = 0; i < counter; i++)
                {
                    if (numbers[i] % 2 == 0)
                    {
                        int convertedDigit = numbers[i] * numbers[i];
                        convertedNumbers.Add(convertedDigit);
                    }
                    if (numbers[i] % 2 == 1 && i != 0 && i != counter - 1)
                    {
                        int convertedDigit = numbers[i - 1] + numbers[i] + numbers[i + 1];
                        convertedNumbers.Add(convertedDigit);
                    }
                    if (numbers[i] % 2 == 1 && i == counter - 1)
                    {
                        int convertedDigit = numbers[i - 1] + numbers[i];
                        convertedNumbers.Add(convertedDigit);
                    }
                    if (numbers[i] % 2 == 1 && i == 0)
                    {
                        int convertedDigit = numbers[i + 1] + numbers[i];
                        convertedNumbers.Add(convertedDigit);
                    }
                }
                foreach (var item in convertedNumbers)
                {
                    if (item / 10 == 0)
                    {
                        finalNumbers.Add(item);
                    }
                    if (item / 10 > 0)
                    {
                        int helpAdd = item / 10;
                        int help = item % 10;
                        finalNumbers.Add(helpAdd);
                        finalNumbers.Add(help);
                        counter++;
                    }
                }
                if (marker == "\\")
                {
                    int[,] matrix = new int[counter, counter];

                    for (int i = 0; i < matrix.GetLength(0); i++)
                    {
                        for (int j = 0; j < matrix.GetLength(1); j++)
                        {
                            if (j == i)
                            {
                                matrix[i, j] = finalNumbers[i];
                                Console.Write(matrix[i, j] + " ");



                            }
                            else
                            {
                                matrix[i, j] = 0;
                                Console.Write(matrix[i, j] + " ");
                            }

                        }
                        Console.WriteLine();
                    }
                }
                int lastElement = counter - 1;
                int element = 0;
                if (marker == "/")
                {
                    int[,] matrix = new int[counter, counter];
                    for (int i = 0; i < matrix.GetLength(0); i++)
                    {
                        for (int j = 0; j < matrix.GetLength(1); j++)
                        {
                            if (j == lastElement)
                            {
                                matrix[i, j] = finalNumbers[lastElement];
                                Console.Write(matrix[i, j] + " ");
                            }
                            else
                            {
                                matrix[i, j] = 0;
                                Console.Write(matrix[i, j] + " ");
                            }
                        }
                        Console.WriteLine();
                        lastElement--;
                    }
                }
            }
        }
    }
}