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: Accepted)

import java.util.*;
import java.math.RoundingMode;
import java.math.BigDecimal;
 
 
 
public class Main{
	 public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long n = sc.nextLong();
		String ans = "";
		while(n>0) {
			if(n%26==1) {
				ans = 'a'+ans;
				n=n/26;
				
			}
			else if(n%26==2) {
				ans='b'+ans;
				n=n/26;
				
			}
			else if(n%26==3) {
				ans='c'+ans;
				n=n/26;
				
			}
			else if(n%26==4) {
				ans='d'+ans;
				n=n/26;
				
			}
			else if(n%26==5) {
				ans='e'+ans;
				n=n/26;
				
			}
			else if(n%26==6) {
				ans='f'+ans;
				n=n/26;
				
			}
			else if(n%26==7) {
				ans='g'+ans;
				n=n/26;
				
			}
			else if(n%26==8) {
				ans='h'+ans;
				n=n/26;
				
			}
			else if(n%26==9) {
				ans='i'+ans;
				n=n/26;
				
			}
			else if(n%26==10) {
				ans='j'+ans;
				n=n/26;
				
			}
			else if(n%26==11) {
				ans='k'+ans;
				n=n/26;
				
			}
			else if(n%26==12) {
				ans='l'+ans;
				n=n/26;
				
			}
			else if(n%26==13) {
				ans='m'+ans;
				n=n/26;
				
			}
			else if(n%26==14) {
				ans='n'+ans;
				n=n/26;
				
			}
			else if(n%26==15) {
				ans='o'+ans;
				n=n/26;
				
			}
			else if(n%26==16) {
				ans='p'+ans;
				n=n/26;
				
			}
			else if(n%26==17) {
				ans='q'+ans;
				n=n/26;
				
			}
			else if(n%26==18) {
				ans='r'+ans;
				n=n/26;
				
			}
			else if(n%26==19) {
				ans='s'+ans;
				n=n/26;
				
			}
			else if(n%26==20) {
				ans='t'+ans;
				n=n/26;
				
			}
			else if(n%26==21) {
				ans='u'+ans;
				n=n/26;
				
			}
			else if(n%26==22) {
				ans='v'+ans;
				n=n/26;
				
			}
			else if(n%26==23) {
				ans='w'+ans;
				n=n/26;
				
			}
			else if(n%26==24) {
				ans='x'+ans;
				n=n/26;
				
			}
			else if(n%26==25) {
				ans='y'+ans;
				n=n/26;
				
			}
			else if(n%26==0) {
				ans='z'+ans;
				n=n/26-1;
				
			}
		}
		System.out.println(ans);
	 }
}