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)

########関数部分##############
def Base_10_to_n(X, n):
    X -= 1
    if (int(X/n)):
            return Base_10_to_n((X)//n, n) + str(X%n) + " "
    return str(X%n) + " "
############################

def nanketa(X):
    n = 1
    a = 0
    while X > (26 ** n) + a:
        a += 26 ** n
        n += 1
    return n


#####関数をつかってみる．#####
######今回は二進数に変換######
x10 = int(input())
x2 = Base_10_to_n(x10, 26)
##print(x2)
ans = ""
a = ""
cnt = 0
x2 = list(x2.split(" "))[:-1]
x2 = list(map(int, x2))
#if x2[-1] == 25:
    #x2[-1] = -1
#x2[-1] += 1
print(x2)
for x in x2:
    ans += chr(x + 97)

print(ans)