using System;
using System.Collections.Generic;
using System.Text;

class Base10ToBase26Letters
{
    static void Main()
    {

        int numberBase10 = 254864;

        List<int> convertedOnlyNum = ConverFromBase10ToBase26(numberBase10);
        Console.WriteLine(ConvertNumToLetter(convertedOnlyNum));

    }
    static List<int> ConverFromBase10ToBase26(int numberBase10)
    {
        List<int> numbersBase26 = new List<int>();
        int res = 0;

        while (numberBase10 > 0)
        {
            res = numberBase10 / 26;
            numbersBase26.Add(numberBase10 % 26);
            numberBase10 = res;
        }
        numbersBase26.Reverse();
        return numbersBase26;
    }
    static string ConvertNumToLetter(List<int> convertedOnlyNum)
    {
        StringBuilder base26OnlyLetters = new StringBuilder();

        
        foreach (var num in convertedOnlyNum)
        {

            switch (num)
            {
                case 0: base26OnlyLetters.Append("A"); break;
                case 1: base26OnlyLetters.Append("B"); break;
                case 2: base26OnlyLetters.Append("C"); break;
                case 3: base26OnlyLetters.Append("D"); break;
                case 4: base26OnlyLetters.Append("E"); break;
                case 5: base26OnlyLetters.Append("F"); break;
                case 6: base26OnlyLetters.Append("G"); break;
                case 7: base26OnlyLetters.Append("H"); break;
                case 8: base26OnlyLetters.Append("I"); break;
                case 9: base26OnlyLetters.Append("J"); break;
                case 10: base26OnlyLetters.Append("K"); break;
                case 11: base26OnlyLetters.Append("L"); break;
                case 12: base26OnlyLetters.Append("M"); break;
                case 13: base26OnlyLetters.Append("N"); break;
                case 14: base26OnlyLetters.Append("O"); break;
                case 15: base26OnlyLetters.Append("P"); break;
                case 16: base26OnlyLetters.Append("Q"); break;
                case 17: base26OnlyLetters.Append("R"); break;
                case 18: base26OnlyLetters.Append("S"); break;
                case 19: base26OnlyLetters.Append("T"); break;
                case 20: base26OnlyLetters.Append("U"); break;
                case 21: base26OnlyLetters.Append("V"); break;
                case 22: base26OnlyLetters.Append("W"); break;
                case 23: base26OnlyLetters.Append("X"); break;
                case 24: base26OnlyLetters.Append("Y"); break;
                case 25: base26OnlyLetters.Append("Z"); break;
            }
        }
        return base26OnlyLetters.ToString();
    }
}