import java.util.*;
import java.io.*;
class Main{
	public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	 long c=sc.nextLong();
	 String[] letter = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};

	 
	 long i=0;
	 int j=0;
	 String str="";
	 while(c>26)
	 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 }
	 int x = (int)c;
	 str=letter[x-1]+str;
	 
	 
	System.out.println(str);
	
				
		
	}
} import java.util.*; util.* java import java.io.*; io.* java class Main{
	public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	 long c=sc.nextLong();
	 String[] letter = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};

	 
	 long i=0;
	 int j=0;
	 String str="";
	 while(c>26)
	 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 }
	 int x = (int)c;
	 str=letter[x-1]+str;
	 
	 
	System.out.println(str);
	
				
		
	}
} Main public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	 long c=sc.nextLong();
	 String[] letter = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};

	 
	 long i=0;
	 int j=0;
	 String str="";
	 while(c>26)
	 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 }
	 int x = (int)c;
	 str=letter[x-1]+str;
	 
	 
	System.out.println(str);
	
				
		
	} main {
	Scanner sc=new Scanner(System.in);
	 long c=sc.nextLong();
	 String[] letter = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};

	 
	 long i=0;
	 int j=0;
	 String str="";
	 while(c>26)
	 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 }
	 int x = (int)c;
	 str=letter[x-1]+str;
	 
	 
	System.out.println(str);
	
				
		
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) long c=sc.nextLong(); c sc.nextLong() sc.nextLong sc String[] letter = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"}; letter {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"} "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z" long i=0; i 0 int j=0; j 0 String str=""; str "" while(c>26)
	 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 } c>26 c 26 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 } i=c/26 i c/26 c 26 if(c%26==0)
	 	{
	 		i=i-1;
	 	} c%26==0 c%26 c 26 0 {
	 		i=i-1;
	 	} i=i-1 i i-1 i 1 j=(int)(c%26) j (int)(c%26) c 26 if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	} j==0 j 0 {
	 	str=letter[25]+str;

	 	} str=letter[25]+str str letter[25]+str letter[25] letter 25 str {
	 	str=letter[j-1]+str;

	 	} str=letter[j-1]+str str letter[j-1]+str letter[j-1] letter j-1 j 1 str c=i c i int x = (int)c; x (int)c str=letter[x-1]+str str letter[x-1]+str letter[x-1] letter x-1 x 1 str System.out.println(str) System.out.println System.out System System.out str String[] args args
import java.util.*;
import java.io.*;
class Main{
	public static void main(String[] args) {
	Scanner sc=new Scanner(System.in);
	 long c=sc.nextLong();
	 String[] letter = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};

	 
	 long i=0;
	 int j=0;
	 String str="";
	 while(c>26)
	 {
	 	
	 	i=c/26;
	 	if(c%26==0)
	 	{
	 		i=i-1;
	 	}
	 	j=(int)(c%26);
	 	if(j==0){
	 	str=letter[25]+str;

	 	}
	 	else{
	 	str=letter[j-1]+str;

	 	}
	 	c=i;

	 }
	 int x = (int)c;
	 str=letter[x-1]+str;
	 
	 
	System.out.println(str);
	
				
		
	}
}