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: Accepted)

#include "bits/stdc++.h"
using namespace std ;
#define int long long
#define ii pair<int,int>
#define FAST_IO ios_base::sync_with_stdio(false) ;cin.tie(NULL);cout.tie(NULL)
#define ms(x,a) memset(x,(int)(a),sizeof(x))
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define vi vector<int >
#define pb push_back
#define endl '\n'
#define ff first
#define ss second
//const int N = 3e5+7 ;
//const int INF = 1e18 ;
//const int MOD = 1e9 + 7 ;
void go(int n){
	if(n>0){
		n-- ;
		go(n/26) ;
		cout << char(n%26+'a') ;
	}
}
 
void solve(){
	int n ;
	cin >> n ;
	go(n) ;
}

int32_t main(){
	#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	#endif
	FAST_IO ;
	int tt = 1;
//	cin >> tt ;
	while(tt--){
		solve() ;
	}
}