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 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

public class Main {

    public static void main(String[] args) {
        exec();
    }

    static void exec() {
        Scanner sc = new Scanner(System.in);
        long n = sc.nextLong();

        final long a = 26;
        System.out.println(convertTenRadixTo(a, n));
    }

    public static String convertTenRadixTo(long radix, long value) {

        List<Long> list = new ArrayList<>();
        if (radix == 0 || value == 0) {
            return "0";
        }
        
        while (value > 0) {
            list.add(value % radix);
            value = (value / radix);
        }
        StringBuilder builder = new StringBuilder();
        
        for (long number : list) {
            builder.append(RADIX_MAP.get(String.valueOf(number)));
        }
        
        return builder.reverse().toString();
    }

    /**
     * 手抜きのMap
     */
    private static final Map<String, String> RADIX_MAP = new HashMap<String, String>() {
        {
            put("0", "a");put("1", "a"); put("2", "b");
            put("3", "c"); put("4", "d"); put("5", "e"); put("6", "f");
            put("7", "g"); put("8", "h"); put("9", "i"); put("10", "j");
            put("11", "k"); put("12", "l"); put("13", "m"); put("14", "n");
            put("15", "o"); put("16", "p"); put("17", "q"); put("18", "r");
            put("19", "s"); put("20", "t"); put("21", "u"); put("22", "v");
            put("23", "w"); put("24", "x"); put("25", "y"); put("26", "z");
        }
    };
}