using Microsoft.VisualBasic;

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

public class Program

{

    public static string mInsert(string source, int index, string text){

    return source.Substring(0, index) + text + source.Substring(index);

    }

    public static string ReverseString(string s)

    {

        char[] array = new char[s.Length];

        int forward = 0;

        for (int i = s.Length - 1; i >= 0; i--)

        {

            array[forward++] = s[i];

        }

        return new string(array);

    }

    public static string Encrypt(string text, string key, int step)

    {

            string temp = String.Empty;

            byte[] bytes = Encoding.ASCII.GetBytes(ReverseString(key));

​

            for (int j=0;j<step;j++) {

                temp += Convert.ToBase64String(bytes);

            }

            text = mInsert(text, step, temp);

            text = ReverseString(text);

​

            return text;

    }

    public static string Decrypt(string text, string key, int step)

    {

            string temp = String.Empty;

            byte[] bytes = Encoding.ASCII.GetBytes(ReverseString(key));

​

            for (int j=0;j<step;j++) {

                temp += Convert.ToBase64String(bytes);

            }

            text = ReverseString(text);

            return text.Replace(temp,"");

    }

    public static void Main()

    {

        string encrypted = Encrypt("SAMOTHEBESTHACKEREVER","LOLZ",3);

        string decrypted = Decrypt(encrypted,"LOLZ",3);

        Console.WriteLine("ENCRYPTED: " + encrypted);

        Console.WriteLine("DECRYPTED: " + decrypted);

    }

}