Multiverse_Communication

using System;

class MultiverseCommunication
{
    static int Base = 13;
    static string[] alphabet = { "CHU", "TEL", "OFT", "IVA", "EMY", "VNB", "POQ", "ERI", "CAD", "K-A", "IIA", "YLO", "PLA" };

    static ulong GetPowerOf13(int exp)
    {
        ulong result = 1;
        for (int i = 1; i <= exp; i++)
        {
            result *= (ulong)Base;
        }
        return result;
    }
    static void Main()
    {
        string message = Console.ReadLine();

        ulong result = 0;
        int power = 0;
        for (int i = message.Length - 1 - 2; i >= 0; i -= 3)
        {
            string letter = message.Substring(i, 3);
            int digit = 0;
            for (int j = 0; j < alphabet.Length; j++)
            {
                if (letter == alphabet[j])
                {
                    digit = j;
                    break;
                }
            }

            result += (ulong)digit * GetPowerOf13(power);
            power++;
        }

        Console.WriteLine(result);
    }
}