Spy Hard

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

namespace ConsoleApplication2
{
    class Program
    {
        static string baseConverter(int sum, int key)
        {
            string stringsum = string.Empty;
            while (sum > 0)
            {
                int x = sum % key;
                stringsum = (char)(x >= 0 && x <= 9 ? x + 48 : x + 'A' - 10) + stringsum;
                sum /= key;
            }
            return stringsum;
        }
        static void Main(string[] args)
        {
            int key = int.Parse(Console.ReadLine());
            string message = Console.ReadLine();
            char[] array = message.ToCharArray();
            int counterOfSymbols = array.Length;
            int sum = 0;
            string system = string.Empty;
            for (int i = 0; i < array.Length; i++)
            {
                char number = array[i];

                if (Char.IsLetter(number))
                {
                    int index = char.ToUpper(number) - 64;
                    sum += index;
                }
                else
                {
                    int asciiNumber = (int)number;
                    sum += asciiNumber;
                }
            }

            Console.WriteLine("{0}{1}{2}", key, counterOfSymbols, baseConverter(sum, key));
        }
    }
}