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: Wrong Answer)

import math
N = int(input())
check = "abcdefghijklmnopqrstuvwxyz"

if N <= 26:
  print(check[N-1])
  exit(0)
i = 1
keta = 26**i 
while keta < N:
  i += 1
  keta = 26**i +keta
if keta == N:
  print("z"*(i))
  exit(0)

if N%26**i ==0:
  print("y"+"z"*(i-1))
  exit(0)
ans = ""
for j in range(i):
  checker = math.floor(N / 26**(i - j-1 ))
  if checker > 26:
    cheker = 26
  N = N - checker*(26**(i-j-1))
  s = check[checker-1]
  ans = ans + s
print(ans)