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 <bits/stdc++.h>
using namespace std;


void revStr(char* str){
	int size = strlen(str);
	int i,j;
	char tmp = {0};
	
	for(i = 0, j = size - 1; i < size / 2; i++, j--){
		tmp = str[i];
		str[i] = str[j];
		str[j] = tmp;
	}
	
	return;	
}
  

int main()
{
  long long N;
  cin >> N;
  
  char str[]="abcdefghijklmnopqrstuvwxyz";
  //str[0]=aでstr[1]=b;
  

  
  
  char name[15];
  int amari;
  
  for(int i=0; i<15 ; i++){
    amari=N%26;
    name[i]=str[amari-1];
    N= N/26;
  }
    
 // for(int i=0;i<15;i++){
 //   cout << name[14-i];
 // }
  revStr(name);
  cout <<name << endl;
   return 0;
}