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 <iostream>
#include <list>
#include <set>
#include <vector>
#include <stdio.h>
#include <algorithm>
#include <queue>

using namespace std;
using P=pair<int,int>;
#define rep(i, n) for (int i = 0; i < n; i++)

int main(){

  long long n;
  string ans="";
  cin >> n;

  while(1){
    int a= n%26;
    long long x=n/26;
    if (a==1)ans ="a"+ans;
    if (a==2)ans = "b" +ans;
    if (a==3)ans = "c"+ans;
    if (a==4)ans = "d"+ans;
    if (a==5)ans = "e"+ans;
    if (a==6)ans = "f"+ans;
    if (a==7)ans = "g"+ans;
    if (a==8)ans = "h"+ans;
    if (a==9)ans = "i"+ans;
    if (a==10)ans = "j"+ans;
    if (a==11)ans = "k"+ans;
    if (a==12)ans = "l"+ans;
    if (a==13)ans = "m"+ans;
    if (a==14)ans = "n"+ans;
    if (a==15)ans = "o"+ans;
    if (a==16)ans = "p"+ans;
    if (a==17)ans = "q"+ans;
    if (a==18)ans = "r"+ans;
    if (a==19)ans = "s"+ans;
    if (a==20)ans = "t"+ans;
    if (a==21)ans = "u"+ans;
    if (a==22)ans = "v"+ans;
    if (a==23)ans = "w"+ans;
    if (a==24)ans = "x"+ans;
    if (a==25)ans = "y"+ans;
    if (a==26)ans = "z"+ans;

    if (n<27)break;
    else n=x;
   }
  std::cout << ans <<endl;
}