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

using namespace std;
#include <vector>
#define rep(i,n) for (ll i = 0; i < (n) ; i++)
#define INF 1e9
#define llINF 1e18
#define base10_4 10000      //1e4
#define base10_5 100000     //1e5
#define base10_6 1000000    //1e6
#define base10_7 10000000   //1e7
#define base10_8 100000000  //1e8
#define base10_9 1000000000 //1e9

#define MOD 1000000007
#define pb push_back
#define ll long long
#define ld long double
#define ull unsigned long long
#define vint vector<int>
#define vll vector<ll>

//#include <stack>
//#include <queue>

// #include <iomanip>
//  cout << fixed << setprecision(15) << y << endl;

string ans_Yes = "Yes"; 
string ans_No = "No"; 
string ans_yes = "yes"; 
string ans_no = "no"; 

ll A;
ll B;
ll C;
ll N;
ll M;
ll K;

ll ltmp;
string stmp;
double dtmp;

int main(){

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> N;
    //N = 1000000000000001;
    ll num_mozi;

    ltmp = N;
    ll base = 26;
    while(ltmp>base){
        ltmp -= base;
        base*=26;
        num_mozi++;
    }

    base = base/26;
    //cout << num_mozi << endl;
    //cout << ltmp << endl;
    //cout << base << endl;
    ltmp = N ;
    string S = "";
    ll val = ltmp % 26;
    S = char('a'+val-1) + S;
    ltmp -= val;

    while(ltmp>0){
        ltmp = ltmp / 26;
        val = ltmp % 26;
        ltmp -= val;
        if(val==0) val = 26;
        S = char('a'+val-1) + S;
    }

    cout << S;



    

}