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: Wrong Answer)

import java.util.Scanner;

public class Main{
  public static void main(String[] args){
	  Scanner sc = new Scanner(System.in);
	  long n=sc.nextLong();
	  StringBuilder s=new StringBuilder();
	  while(true) {
		  if(n%26==1) {
			  s.append("a");
		  }else if(n%26==2) {
			  s.append("b");
		  }else if(n%26==3) {
			  s.append("c");
		  }else if(n%26==4) {
			  s.append("d");
		  }else if(n%26==5) {
			  s.append("e");
		  }else if(n%26==6) {
			  s.append("f");
		  }else if(n%26==7) {
			  s.append("g");
		  }else if(n%26==8) {
			  s.append("h");
		  }else if(n%26==9) {
			  s.append("i");
		  }else if(n%26==10) {
			  s.append("j");
		  }else if(n%26==11) {
			  s.append("k");
		  }else if(n%26==12) {
			  s.append("l");
		  }else if(n%26==13) {
			  s.append("n");
		  }else if(n%26==14) {
			  s.append("m");
		  }else if(n%26==15) {
			  s.append("o");
		  }else if(n%26==16) {
			  s.append("p");
		  }else if(n%26==17) {
			  s.append("q");
		  }else if(n%26==18) {
			  s.append("r");
		  }else if(n%26==19) {
			  s.append("s");
		  }else if(n%26==20) {
			  s.append("t");
		  }else if(n%26==21) {
			  s.append("u");
		  }else if(n%26==22) {
			  s.append("v");
		  }else if(n%26==23) {
			  s.append("w");
		  }else if(n%26==24) {
			  s.append("x");
		  }else if(n%26==25) {
			  s.append("y");
		  }else if(n%26==0) {
			  s.append("z");
		  }
		  //System.out.println(s+" "+n);
		  if(n<=26)break;
		  if(!s.substring(s.length()-1, s.length()).equals("z")) {
			  n=n/26;
		  }else {
			  n=n/26-1;
		  }
	  }
	  System.out.println(s.reverse());
  }
}