Encrypted Matrix

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

namespace _04EncryptedMatrix
{
    class Program
    {
        static void Main()
        {
            string input = Console.ReadLine();
            char[] inputChar = input.ToCharArray();
            char[] concat = new char[inputChar.Length];
            char[] concat2 = new char[concat.Length];
            char[] newNumber = new char[concat2.Length];
           // char[] newnewNumber = new char[newNumber.Length];
            string slash = Console.ReadLine();
            for (int i = 0; i < inputChar.Length; i++)
            {
                char lastDigit = Convert.ToChar(inputChar[i] % 10);

                concat[i]=Convert.ToChar(lastDigit);
            }
            for (int i = 0; i < concat.Length; i++)
            {
                 if ((int)concat[i] % 2 == 0)
                 {
                    newNumber[i] = (char)(concat[i] * concat[i]);


                 }
                    else if ((int)concat[i] % 2 != 0 && (i==0))
                    {

                        newNumber[i] = (char)(Convert.ToInt32(concat[i + 1])+ Convert.ToInt32(concat[i]));
                    }
                    else if ((int)concat[i] % 2 != 0 && (i == concat.Length - 1))
                    {
                        newNumber[i] = (char)(Convert.ToInt32((concat[i - 1])+Convert.ToInt32(concat[i]) ));
                    }
                 else if (((int)concat[i] % 2 != 0) && (i!=0) && (i!=concat.Length-1))
                    {
                        newNumber[i] = (char)(Convert.ToInt32(concat[i - 1]) + Convert.ToInt32(concat[i + 1]) + Convert.ToInt32(concat[i]));
                    }

            }

            char[,] matrix = new char[newNumber.Length, newNumber.Length];
            if (slash == "\\")
            {
                for (int i = 0; i < newNumber.Length; i++)
                {
                    matrix[i, i] = newNumber[i];
                }
            }
            else
            {

                    for (int i = 0; i < newNumber.Length; i++)
                    {
                        matrix[newNumber.Length - i - 1, i] = newNumber[i];
                    }
            }
            char[] characters = newNumber.ToString().ToCharArray();

            for (int i = 0; i < newNumber.Length; i++)
	   {
                 for (int j = 0; j < newNumber.Length; j++)
                 {

                  Console.Write((int)matrix[i,j]+ " ");

                  }
                   Console.WriteLine();
            }

        }
    }
}