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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

"use strict";

function main(input) {
  const alphabet = "abcdefghijklmnopqrstuvwxyz";
  const alphabet_arr = alphabet.split("");
  input = input.trim();
  const az = 26;
  let num = parseInt(input);
  let n = 1; //桁数
  let m = 0;
  let ans = [];

  while (num > 26) {
    n++;
    const a = num % az;
    ans.push(a);
    num = Math.floor(num / az);
  }
  ans.push(num % az);
  for (let i in ans) {
    ans[i] = alphabet_arr[ans[i] - 1];
  }
  console.log(ans.reverse().join(""));
}
var f = function (a, b) {
  return a - b;
};

main(require("fs").readFileSync("/dev/stdin", "utf-8"));