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)

#x = 1000000000000001
x=int(input())
list_Shou=[]
list_New = []
list_Alphabet = [""]
for i in range(97, 97+26):
    list_Alphabet.append(chr(i))

for i in range(1, 11)[::-1]:
    Warukazu = 26**i
    Shou = min(x//Warukazu,26)
    Amari = x - (Shou*Warukazu)
    print(str(Warukazu)+"="+str(Shou)+"..."+str(Amari))
    
    if Amari==26**(i-1)  and Shou>0:
        Shou+=-1#shouを１減らして
        Amari+=Warukazu#Amariを割る数ぶん増やす
        print("New"+str(Shou)+"/"+str(Amari))
        
    list_Shou.append(Shou)
    x=Amari
    
    #list_Shou.append(Amari+Shou*26)#ひとけため：if Amari==0の処理がいらないので、for文からくくりだす

print(list_Shou)
#リストをアルファベットに変換

for j in list_Shou:
    list_New.append(list_Alphabet[j])
print(list_New)
Answer = "".join(list_New)
print(Answer)