Problem:
Score : 300 points

Problem Statement

1000000000000001 dogs suddenly appeared under the roof of Roger's house, all of which he decided to keep. The dogs had been numbered 1 through 1000000000000001, but he gave them new names, as follows:

the dogs numbered 1,2,\cdots,26 were respectively given the names a, b, ..., z;

the dogs numbered 27,28,29,\cdots,701,702 were respectively given the names aa, ab, ac, ..., zy, zz;

the dogs numbered 703,704,705,\cdots,18277,18278 were respectively given the names aaa, aab, aac, ..., zzy, zzz;

the dogs numbered 18279,18280,18281,\cdots,475253,475254 were respectively given the names aaaa, aaab, aaac, ..., zzzy, zzzz;

the dogs numbered 475255,475256,\cdots were respectively given the names aaaaa, aaaab, ...;

and so on.

To sum it up, the dogs numbered 1, 2, \cdots were respectively given the following names:

a, b, ..., z, aa, ab, ..., az, ba, bb, ..., bz, ..., za, zb, ..., zz, aaa, aab, ..., aaz, aba, abb, ..., abz, ..., zzz, aaaa, ...

Now, Roger asks you:

"What is the name for the dog numbered N?"

Constraints

N is an integer.

1 \leq N \leq 1000000000000001

Input

Input is given from Standard Input in the following format:

N

Output

Print the answer to Roger's question as a string consisting of lowercase English letters.

Sample Input 1

2

Sample Output 1

b

Sample Input 2

27

Sample Output 2

aa

Sample Input 3

123456789

Sample Output 3

jjddja

Solution in C# (.NET Core 3.1.201) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;

namespace ProgramingTest
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            string lines = System.Console.ReadLine();
            int number = int.Parse(lines);
            //Console.WriteLine(number);

            //List<int> amari = new List<int>();
            int[] amari = new int[number];

            int index = 0;

            while (number > 26)
            {
                //Console.WriteLine(number);

                amari[index] = number % 26;

                //Console.WriteLine(amari[index]);

                //if (number == 0)
                //{
                //    break;
                //}
                int sho = number / 26;
                //Console.WriteLine(sho);

                //number -= 26 * sho;

                number = sho;
                //Console.WriteLine(number);


                //Console.WriteLine(sho);

                index += 1;
            }



            amari[index] = number;
            //Console.WriteLine(amari[index]);


            char[] kotae = new char[index+1];
            string[] kotae2 = new string[index + 1];



            //for (int i=0; i<index+1; i++)
            //{
            //    Console.WriteLine(amari[i]);
            //}


            for (int i = 0; i < index + 1; i++)
            {
                string s2 = ((char)(amari[i] + 64)).ToString().ToLower();
                //char s = ((char)(amari[i] + 64));

                char s = s2[0];

                kotae[i] = s;

            }
            Array.Reverse(kotae);

            Console.WriteLine(kotae);






        }
    }
}