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())

num = int(math.log(1000000000000001, 26))
#print(num)

#余り
y, z = n, n
y_lis = []
#商
for i in range(num + 1):
    if z >= 1:
        y_lis.append(z % 26)
        z = z // 26
    elif z == 0:
            break
print(y_lis)


for i in range(len(y_lis) - 1):
    if y_lis[i] == 0:
        y_lis[i] = 26
        y_lis[i + 1] -= 1

if y_lis[-1] == 0:
    y_lis.remove(y_lis[-1])
print(y_lis)
y_lis = list(reversed(y_lis))
ans = ""
for i in range(len(y_lis)):
    y_lis[i] = chr(y_lis[i] + 96)
    ans += y_lis[i]
print(ans)