import java.util.Scanner;

public class Main {
   public static void main(String[] args) {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   }
} import java.util.Scanner; Scanner java.util public class Main {
   public static void main(String[] args) {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   }
} Main public static void main(String[] args) {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   } main {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   } Scanner s = new Scanner(System.in); s new Scanner(System.in) long n = s.nextLong(); n s.nextLong() s.nextLong s int rem=0; rem 0 String name = ""; name "" char c; c while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       } n>0 n 0 {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       } rem =(int) ((n-1) % 26) rem (int) ((n-1) % 26) (n-1) n 1 26 c = (char)('a'+rem) c (char)('a'+rem) 'a' rem name+=c name c n= (n-1) /26 n (n-1) /26 (n-1) n 1 26 for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       } int i=name.length()-1; int i=name.length()-1; i name.length()-1 name.length() name.length name 1 i>=0 i 0 i-- i-- i {
           System.out.print(name.charAt(i));
       } {
           System.out.print(name.charAt(i));
       } System.out.print(name.charAt(i)) System.out.print System.out System System.out name.charAt(i) name.charAt name i String[] args args public class Main {
   public static void main(String[] args) {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   }
} public class Main {
   public static void main(String[] args) {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   }
} Main
import java.util.Scanner;

public class Main {
   public static void main(String[] args) {
       Scanner s = new Scanner(System.in);
       long n = s.nextLong();
       int rem=0;
       String name = "";
       char c;
       while(n>0) {
           rem =(int) ((n-1) % 26);
           c = (char)('a'+rem);
           name+=c;
           n= (n-1) /26;
       }
       for(int i=name.length()-1;i>=0;i--) {
           System.out.print(name.charAt(i));
       }
   }
}
