Multiverse Communication [Telerik] (100/100)

using System;
using System.Collections.Generic;

namespace MultiverseCommunication
{
    class MultiverseCommunication
    {
        static void Main()
        {
            string input = Console.ReadLine();
            Dictionary<string,decimal> dict = new Dictionary<string, decimal>();
            dict.Add("CHU",0);
            dict.Add("TEL",1);
            dict.Add("OFT",2);
            dict.Add("IVA",3);
            dict.Add("EMY",4);
            dict.Add("VNB",5);
            dict.Add("POQ",6);
            dict.Add("ERI",7);
            dict.Add("CAD",8);
            dict.Add("K-A",9);
            dict.Add("IIA",10);
            dict.Add("YLO",11);
            dict.Add("PLA",12);
            decimal result = 0M;
            for (decimal i = input.Length-3, k = 1; i >= 0; i-=3,k*=13)
            {
                char one = input[(int)i];
                char two = input[(int)i + 1];
                char three = input[(int)i + 2];
                string temp = one +""+ two +""+ three;
                if (dict.ContainsKey(temp))
                {
                    result += k*dict[temp];
                }
            }
            Console.WriteLine(result);
        }
    }
}