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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

/*
    Author: @__goku__
            ssrivastava990@gmail.com
 
                   `\-.   `
                      \ `.  `
                       \  \ |
              __.._    |   \.       S O N - G O K U
       ..---~~     ~ . |    Y
         ~-.          `|    |
            `.               `~~--.
              \                    ~.
               \                     \__. . -- -  .
         .-~~~~~      ,    ,            ~~~~~~---...._
      .-~___        ,'/  ,'/ ,'\          __...---~~~
            ~-.    /._\_( ,(/_. 7,-.    ~~---...__
           _...>-  P""6=`_/"6"~   6)    ___...--~~~
            ~~--._ \`--') `---'   9'  _..--~~~
                  ~\ ~~/_  ~~~   /`-.--~~
                    `.  ---    .'   \_
                      `. " _.-'     | ~-.,-------._
                  ..._../~~   ./       .-'    .-~~~-.
            ,--~~~ ,'...\` _./.----~~.'/    /'       `-
        _.-(      |\    `/~ _____..-' /    /      _.-~~`.
       /   |     /. ^---~~~~       ' /    /     ,'  ~.   \
      (    /    (  .           _ ' /'    /    ,/      \   )
      (`. |     `\   - - - - ~   /'      (   /         .  |
       \.\|       \            /'        \  |`.           /
       /.'\\      `\         /'           ~-\         .  /\
      /,   (        `\     /'                `.___..-      \
     | |    \         `\_/'                  //      \.     |
     | |     |                 _Seal_      /' |       |     |
 */

import java.io.*;
import java.util.*;

public class Main
{
    static PrintWriter out = new PrintWriter((System.out));

    public static void main(String args[]) throws IOException
    {
        Kioken sc = new Kioken();
        long num=sc.nextLong();
        StringBuilder ans=new StringBuilder("");
        int p=26;
        while(num!=0)
        {
            long d=num%26;
            if(d==0)
            {
                d=26;
            }
            ans.append((char)(d+64));
            num=num-d;
            num/=p;
        }
        ans.reverse();
        out.println(ans.toString().toLowerCase());
        out.close();
    }

    public static void kamehameha()
    {
    }

    static class Kioken
    {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer("");

        public String next()
        {
            while (!st.hasMoreTokens())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        public int nextInt()
        {
            return Integer.parseInt(next());
        }

        public long nextLong()
        {
            return Long.parseLong(next());
        }

        public double nextDouble()
        {
            return Double.parseDouble(next());
        }

        public String nextLine()
        {
            try
            {
                return br.readLine();
            } catch (Exception e)
            {
                e.printStackTrace();
            }
            return null;
        }

        public boolean hasNext()
        {
            String next = null;
            try
            {
                next = br.readLine();
            } catch (Exception e)
            {
            }
            if (next == null)
            {
                return false;
            }
            st = new StringTokenizer(next);
            return true;
        }
    }
}