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 Python (3.8.2) (judge verdict: Accepted)

#!/usr/bin/env python3
import sys
from itertools import chain

# form bisect import bisect_left, bisect_right, insort_left, insort_right
# from collections import Counter
# import numpy as np


def solve(N: int):
    az = "abcdefghijklmnopqrstuvwxyz"
    N -= 1
    answer = ""
    while True:
        answer = az[N % 26] + answer
        N = N // 26
        if N == 0:
            break
        N = N - 1
    return answer


def main():
    tokens = chain(*(line.split() for line in sys.stdin))
    # N = map(int, line.split())
    N = int(next(tokens))  # type: int
    answer = solve(N)
    print(answer)


if __name__ == "__main__":
    main()