import java.util.*;
public class Main
{
	public static void main(String[] args) {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	}                                       
   	private String getCharForNumber(long i) {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } 
} import java.util.*; util.* java public class Main
{
	public static void main(String[] args) {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	}                                       
   	private String getCharForNumber(long i) {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } 
} Main public static void main(String[] args) {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	} main {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	} Main m=new Main(); m new Main() Scanner sc=new Scanner(System.in); sc new Scanner(System.in) long n=sc.nextLong(); n sc.nextLong() sc.nextLong sc String value=""; value "" String val=""; val "" while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     } n>0 n 0 {
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     } long rem=n % 26; rem n % 26 n 26 if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     } rem==0 rem 0 {
	     val="Z";
	     value=val+value;    
	     } val="Z" val "Z" value=val+value value val+value val value {
	     value=m.getCharForNumber(rem)+value;
	     } value=m.getCharForNumber(rem)+value value m.getCharForNumber(rem)+value m.getCharForNumber(rem) m.getCharForNumber m rem value n=n-1 n n-1 n 1 n=n/26 n n/26 n 26 System.out.println(value.toLowerCase()) System.out.println System.out System System.out value.toLowerCase() value.toLowerCase value String[] args args private String getCharForNumber(long i) {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } getCharForNumber {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : ""; i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "" i > 0 && i < 27 i > 0 i 0 i < 27 i 27 String.valueOf((char)(i + 64)) String.valueOf String (char)(i + 64) i 64 "" long i i public class Main
{
	public static void main(String[] args) {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	}                                       
   	private String getCharForNumber(long i) {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } 
} public class Main
{
	public static void main(String[] args) {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	}                                       
   	private String getCharForNumber(long i) {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } 
} Main
import java.util.*;
public class Main
{
	public static void main(String[] args) {
	    Main m=new Main();
	    Scanner sc=new Scanner(System.in);
	    long n=sc.nextLong();
	    String value="";
	    String val="";
	    while(n>0){
	     long rem=n % 26;
	     if(rem==0){
	     val="Z";
	     value=val+value;    
	     }
	     else{
	     value=m.getCharForNumber(rem)+value;
	     }
	     n=n-1;
	     n=n/26;
	     }
	    System.out.println(value.toLowerCase()); 
	}                                       
   	private String getCharForNumber(long i) {
    return i > 0 && i < 27 ? String.valueOf((char)(i + 64)) : "";
   } 
}
