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++ (Clang 10.0.0) (judge verdict: Accepted)

#include <iostream>
#include <string.h>
#include <cstring>
#include <math.h>
#include <algorithm>
#include <functional>
#include <stack>
#include <queue>
#include <vector>
#include <map>
using namespace std;

#define cio ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define ll long long
#define ii pair < int, int >
#define iii pair < int, ii >
#define INF 987654321
#define LINF 987654321987654321

int main()
{
	cio;
	ll n;
	cin >> n;

	int arr[30];
	int i = 0;

	while (n)
	{
		arr[i++] = n % 26;
		n /= 26;
	}
	i--;

	for (int k = 0; k < i; k++)
	{
		if (arr[k] <= 0)
		{
			arr[k] += 26;
			arr[k + 1] -= 1;
		}
	}

	for (; i >= 0; i--)
	{
		if(arr[i] > 0)
			cout << (char)('a' + arr[i] - 1);
	}
}