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: Runtime Error)

n = int(input())
chars = 'Xabcdefghijklmnopqrstuvwxyz'
res = ''
while True:
    x = n%26 #最下位の位の文字を求める(係数が26でない最下位の位が余りとして出せる)
    if x == 0:#Xが26のときのみ余り0で対応させるため26に書き換え
        x = 26
    res += chars[x]#文字を正解リストに追加
    n -= x　#xを左辺に持っていって右辺で10の位以上の数値を調べる
    if n == 0 :
        break
    n //= 26 #n-xは必ず26の倍数になっている。(xを移項しているから自明)
    #最下位の位を余りとして扱うために26で割って係数を消している。
print(res[::-1])#resには1の位が一番初めに入っているので、反転させて表示