using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp12
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btn1_Click(object sender, EventArgs e)
        {
            int n = txtUnos.Text.Trim().Length;

            if (n > 25)
            {
                MessageBox.Show("Unesi manje!");
                return;
            }
            else
            {
                char[,] niz = new char[n, n];
                int k = 0;
                string str = "";
                char pom = ' ';
                int count = 0, zbir1 = 0, zbir2 = 0;
                List<char> lista1 = new List<char>();
                List<char> lista2 = new List<char>();

                for (int i = 0; i < n; i++)
                {
                    for (int j = 0; j < n; j++)
                    {
                        if (Convert.ToInt32(txtUnos.Text[j]) + k > 90)
                        {
                            niz[i, j] = Convert.ToChar((Convert.ToInt32(txtUnos.Text[j]) + k) - 26);
                        }
                        else
                        {
                            niz[i, j] = Convert.ToChar(Convert.ToInt32(txtUnos.Text[j]) + k);
                        }
                        str += niz[i, j].ToString() + " ";
                    }
                    k++;
                    str += "\n";
                }

                richTextBox1.Text = str;

                for(int i = 0; i < n - 1; i++)
                {
                    for (int j = 0; j < n; j++)
                    {
                        if (i == j)
                        {
                            if (niz[i, j] == niz[i + 1, j + 1])
                            {
                                MessageBox.Show(niz[i, j].ToString());
                            }
                        }
                        if (i + j == n - 1)
                        {
                            if (niz[i, j] == niz[i + 1, j - 1])
                            {
                                MessageBox.Show(niz[i, j].ToString());
                            }
                        }
                    }
                }
            }
        }
    }
}