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 C (GCC 9.2.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <math.h>

int main(){
    int n;
    int mozi;

    scanf("%d",&n);

    //a~z:1~26 aa~zz:27~27+26*26 aaa~zzz;27~27+26*26+26^3
int i = 1;
int sum = pow(26,1);
while (n >= sum){
    i++;
    sum += pow(26,i);
    
    
}
mozi = i;

char name[mozi];
//name[mozi-1] =  'a'+(n - pow(26,i) -1);
int m = n;
for (int k=0;k<mozi;k++){

    name[k] = m/(pow(26,i-1-k));
    m = m - pow(26,i-1-k)*name[k];
    
    
    printf("%d\n",name[k]);
}
    
for (int k=0;k<mozi;k++){
    name[k] = 'a' + name[k] - 1;
    }


printf("%s\n",name);
return 0;
}