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 Java (OpenJDK 11.0.6) (judge verdict: Runtime Error)

import java.io.*;
import java.util.*;

public class Main {

	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

	public static int nextInt() throws IOException {
		return Integer.parseInt(br.readLine());
	}

	public static long nextLong() throws IOException {
		return Long.parseLong(br.readLine());
	}

	public static String next() throws IOException {
		return br.readLine();
	}

	public static int[] sortArr(int arr[]) throws IOException {
		ArrayList<Integer> a = new ArrayList<Integer>();
		for (int i : arr)
			a.add(i);

		Collections.sort(a);

		for (int i = 0; i < a.size(); i++)
			arr[i] = a.get(i);
		return arr;
	}

	public static int[] desortArr(int arr[]) throws IOException {
		ArrayList<Integer> a = new ArrayList<Integer>();
		for (int i : arr)
			a.add(i);

		Collections.sort(a, Collections.reverseOrder());

		for (int i = 0; i < a.size(); i++)
			arr[i] = a.get(i);
		return arr;
	}

	public static int[] nextArr() throws IOException {
		String elements[] = br.readLine().split(" ");
		int arr[] = new int[elements.length];
		for (int j = 0; j < elements.length; j++)
			arr[j] = Integer.parseInt(elements[j]);
		return arr;
	}

	public static void printArr(char arr[]) {
		for (int i = 0; i < arr.length; i++)
			System.out.print(arr[i] + " ");
	}

	public static void main(String[] args) throws IOException {

		int T = 1;
		while (T-- > 0) {
			int n = nextInt();
			
			StringBuilder s = new StringBuilder(" ");

			while (n > 0) {
				n--;
				s.append((char) (97 + n % 2));
				n = n / 26;
			}
			System.out.println(s.reverse());
		}
	}

}