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>

long int po(long int x,int n){
  if(n==0)
    return 1;
  else
    return x*po(x,n-1);
}

int main(void){
  long int N,tmp;
  scanf("%ld",&N);
  int p[11];
  int i;
  for(i=10;i>0;i--){
    tmp=po(26,i);
    if(N>tmp){
      p[i]=N/tmp;
      N=N%tmp;
    }else p[i]=0;
    
    if(p[i]==26){
      for(;i>=0;i--)
	p[i]=26;
      break;
    }
  }
  if(p[0]!=26)
    p[0]=N;
  
  char a='a';
  for(i=10;i>=0;i--)
    if(p[i]!=0)
      printf("%c",a+p[i]-1);
  printf("\n");
  
  return 0;
}