Multiverse

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

class MultiverseCommunication
{
    static void Main()
    {
        string thirtNumSys = Console.ReadLine();
        thirtNumSys = thirtNumSys.Replace(" ", string.Empty);
        thirtNumSys = thirtNumSys.ToUpper();
        string helpVar = string.Empty;
        long sum = 0;

        for (int i = 0, j = thirtNumSys.Length / 3 - 1; i < thirtNumSys.Length; i = i + 3, j--)
        {
            helpVar = thirtNumSys.Substring(i, 3);
            switch (helpVar)
            {
                case "CHU": sum += 0; ; break;
                case "TEL": sum += 1 * PowerOgThirteen(j); break;
                case "OFT": sum += 2 * PowerOgThirteen(j); break;
                case "IVA": sum += 3 * PowerOgThirteen(j); break;
                case "EMY": sum += 4 * PowerOgThirteen(j); break;
                case "VNB": sum += 5 * PowerOgThirteen(j); break;
                case "POQ": sum += 6 * PowerOgThirteen(j); break;
                case "ERI": sum += 7 * PowerOgThirteen(j); break;
                case "CAD": sum += 8 * PowerOgThirteen(j); break;
                case "K-A": sum += 9 * PowerOgThirteen(j); break;
                case "IIA": sum += 10 * PowerOgThirteen(j); break;
                case "YLO": sum += 11 * PowerOgThirteen(j); break;
                case "PLA": sum += 12 * PowerOgThirteen(j); break;
                default: ; break;
            }
        }
        Console.Write(sum);
    }
    static long PowerOgThirteen(int power)
    {
        long res = 1;
        for (int i = 0; i < power; i++)
        {
            res *= 13;
        }
        return res;
    }
}